There’s sometimes a point when, as much as you love your Cougar, you might want to make it more of your own car. We’re big fans of people customizing cars, and while modifying cars in general is certainly not a new thing, modifying a Fox Cougar can be challenging, frustrating, rewarding, and satisfying. All at the same time, we may add. There is not an easy road ahead of you, that’s for sure. So what we’d like to do is give you a heads-up about some of the common ways to modify your Cougar, from inside to outside, top to bottom, front to back. Whether you’re looking to just improve upon a few things or are going for a full custom look, this is the section for you.

As always, we’ll guide you along the way but remember: you’re modifying your car at your own risk and we assume no responsibilities for your actions (see our disclaimer for more details). If you have some information that you’d like us to add here, or have a general comment about modifying, feel free to contact us.

Note: Modifications listed below are for all 1983-88 Cougar/Thunderbird models, unless specified otherwise.

5.0L V8 - Standard-to-High Output Conversion


The stock 1986-88 Cougar 5.0L V8 engine is rated at just 150hp (155hp in 1988 due to dual exhaust) from the factory. Sure, it runs great, it provides plenty of low-end torque to get you off the line, and it can get pretty decent fuel economy on the highway. But that’s about the limit of its performance. You may be pining for more power but things can get pretty expensive quickly. What you need is a budget-friendly, economical solution. Well, how does a 75hp gain in one weekend sound to you?

It’s relatively easy to convert your stock 150hp* 5.0L V8 into a near-perfect copy of the legendary 225hp HO 5.0 used in Mustangs. You don’t even need to remove the engine from the car, making it an extremely efficient job.

Keep in mind a few things before you begin collecting parts:

  • This section assumes that you will be using STOCK Ford or Mustang parts.
  • It is also being assumed that you will keep your stock speed density setup. Afterwards it’s possible to do a sass air conversion.
  • To do the full HO (~225hp) conversion, you MUST have all of the parts below before you can start.
  • You must also convert to dual exhaust at the same time you do the HO conversion as the HO motor requires freer breathing.

Once you’ve assembled all the components for the HO conversion you can proceed using the guidelines below.

* This section is for factory SEFI cars only (1986-88). Earlier CFI cars (1983-85) would require a full SEFI conversion plus the information below.


Requirements for HO Conversion in EFI cars:

  • SEFI Fuel Injection
  • E7TE-Casting Cylinder Heads
  • Stock 19 lb/hr Fuel Injectors
  • HO-Specific Camshaft
  • EEC-IV 5.0 HO Computer
  • Higher Volume Fuel Pump



  • HO Upper Intake Manifold
  • HO Throttle Body
  • MAP Sensor
  • 9-Blade Fan


SEFI Fuel Injection

Since your 1986-88 V8 car already has the same SEFI setup as the Mustang, you can simply reuse virtually the whole system, including the fuel lines, metal fuel rails and the stock fuel pressure regulator. See below about the fuel injectors.


E7TE-Casting Cylinder Heads


HO E7 Cylinder Head

The stock 1986 heads are, to say the least, very restrictive. Narrow inlets and “high swirl” exhaust ports add to fuel economy, but at the expense of good power. These heads were used on the ’86-’88 Cougar/Thunderbird, the ’86-’91 Crown Victoria/Grand Marquis, and the ’86 Mustang GT. In ’87, the Mustang 5.0 engine received the F-150 truck heads (E7TE-AA castings, aka E7s), which added approximately 15hp; the Cougars still had the restrictive heads through 1988. You should consider using at least the E7 heads. You can find decent heads in a junkyard, at a swap meet, or online auctions or message boards. Aftermarket heads, such as the GT-40 and Trick Flow among many others, can also be used, according to your budget. By the way, you can put these heads on stock non-HO motors (without converting to HO) just as well. If you cannot find E7s, it’s perfectly okay to use a slightly older Ford 5.0 head (E3, E4, etc.) but avoid reusing the E6s unless you cannot afford E7s or cannot find them.


Stock 19 lb/hr Fuel Injectors


HO 19lb. Injector

Your stock fuel injectors (1986-88 non-HO 5.0) are rated at 14 lb/hr and are light grey in color. The HO computer is set up for 19 lb/hr (orange or tan) injectors. You’ll absolutely need to acquire 19 lb/hr injectors for this conversion; you can use them from a Mustang or a Mark VII. The good news is, they’re fairly plentiful and usually very cheap. Just ask any Mustang guy that’s switched over to 24 lb/hr; he may give you the old 19 lb/hr ones. Or you can check online. In general, fuel injectors are extremely reliable and usually do not malfunction (unless severely clogged), so if you get a good deal on a set, chances are you’ll actually be getting a good deal. By the way, in case you’re curious: if you mix the 19 lb/hr computer with your stock 14 lb/hr injectors, you will get a bad fuel starvation problem and drivability woes. You can’t avoid getting the correct injectors for the HO conversion.


HO-Specific Camshaft


HO Camshaft

In order to work with the Mustang computer and injectors, you must also get a stock ’87-’93 Mustang camshaft. It is the heart of the HO conversion. Ford re-ground cams almost every year for a little better performance and fuel economy, so stock HO cam part numbers changed, but they will all work with the HO computer and you will more than likely never notice any difference between them. It is therefore entirely possible to use a ’92 HO cam with an ’87 Mustang GT computer with no difficulties. Idle with the HO cam is very smooth, and top end is greatly increased over the stock Cougar cam. Generally you can use any 1987-93 HO cam with the speed density computer with great results. It is advised to avoid the 1986 HO cam as the later ones give a lot more usable power. There are lots of Mustang owners out there that would just love to get rid of the stock cam they have lying around (because they put an aftermarket one in)—perhaps you can wrestle one away from them. One note of caution: since we have flat-top pistons from the factory, anything more potent than the stock HO camshaft may result in serious piston-to-valve clearance problems and/or drivability problems. The only other confirmed combination that works with flat top pistons is the Trick Flow cam with TFS heads. By using an HO cam, your firing order will be different from your stock one. The firing order will now be 1-3-7-2-6-5-4-8, using the HO pattern. You’ll need to route the spark plug wires accordingly.


EEC-IV 5.0 HO Computer


HO EEC-IV Computer

Here’s the brains of it all, literally—the stock Mustang 5.0 computer. You should be able to find one at a salvage yard, swap meet or online for a reasonable price. Beginning in 1987 Ford began using a calibration code on each computer, with the code stamped on the top. For speed density, these are the computers that you can use (all listed for automatic transmissions):

  • DA1 (1987-88 Mustang)
  • DB1 (1987-88 Mustang)
  • DX3 (1987 Mark VII)
  • VL2 (1987 Mark VII)
  • DY3 (1988 Mark VII)
  • D9S (1988 Mark VII)

Just FYI, the Mark VII computers are top speed-limited to 105mph. The Mustang HO computers are not.


Higher Volume Fuel Pump


HO Fuel Pump

A stock Mustang/Mark VII uses an 88lph (liters per hour) fuel pump; ours are 65lph stock. To avoid a severe hesitation problem and/or a lean condition, you will need to change your pump to at least an 88lph unit. We recommend at least a 155lph, good quality aftermarket Mustang-style unit (BBK, Walbro, etc.). Avoid parts store pumps as they tend to have a high failure rate. You will only need the pump itself, not the hanger, and you can reuse your sock. The wiring may need to be modified slightly, and you may also need to zip-tie the new pump to your stock hanger, but you can get everything to work with your fuel system. Remember to change the fuel filter not long after changing out the pump.

In case you’re wondering, you may be able to reuse your stock fuel pump if it’s still good and has been recently changed. But as it is, even 65lph was cutting it close for a non-HO 5.0. You might experience a slight fuel starvation, in which case the pump will definitely need upgraded.



HO Upper Intake Manifold (optional)


HO Upper Intake

The HO upper intake should be used as it is better flowing and helps with delivering power to the 5.0 engine. But it is optional because, although there is a minor difference in casting between the non-HO and HO plenums, the difference is simply a few horsepower, estimated at 5-7 hp. The stock Mustang upper (as well as the Mark VII HO upper) has the letters “HO” stamped under the removable top plate. If you decide to go with this intake, you should install the matching EGR plate, EGR valve, and throttle body from the Mustang as well; this will give you maximum airflow performance. So you can still use your stock upper if you like, but you’ll definitely get better airflow with the HO unit. By the way, the non-HO and HO lower intake manifolds are all the same; if you want to reuse your lower that’s fine also.


HO Throttle Body (optional)


HO Throttle Body

The stock Cougar/Thunderbird throttle body is 50mm. The stock Mustang throttle body is better at 60mm. Your stock one will work if you can’t get the bigger one, but your car may bog down slightly upon acceleration due to restricted airflow. Still, you can likely get away with not upgrading if you can’t afford it or just don’t want to at the time of the HO conversion.

A new aftermarket 65mm aftermarket unit will work with the stock speed density computer and give you much improved airflow. Anything over a 65mm-70mm throttle body on a stock motor will decrease low end torque and actually bog down the motor with too much air. Also, the HO upper has a 67mm bore; a 70mm throttle body may create slight turbulence because of this. The bigger units (75mm+) should be limited to severely modified motors and larger-bore upper intakes. Be sure to buy a throttle body made for 1987-up Mustangs—the 1986 throttle bodies were unique. And remember to get a throttle position sensor (TPS) to match the new throttle body, as your stock one may not work on it.


HO EGR Spacer

If you are going to upgrade your throttle body, whether the stock HO 60mm or larger, you will also need its matching EGR spacer plate. The EGR plate and throttle body must match for optimal airflow. The coolant rails are just like your stock ones, so you’ll be able to reuse your coolant hoses on the new throttle body.


MAP Sensor (optional)


HO MAP Sensor

The MAP sensor hangs on the firewall, just above and to the right of the upper intake plenum (just to the left of the wiper motor). This reads the Manifold Absolute Pressure, and since you’ll have a different amount of vacuum with the new camshaft, you may need replace yours. It’s recommended that you try to use yours first. If you experience rough idle, bad starts, no starts, or general bad behavior from the engine, replace this sensor with one that matches the calibration code for your particular EEC-IV HO computer. Now there are tons of part numbers for this sensor so it may take multiple tries to get one that works. Incidentally, the 1989-up mass-air Mustangs have a BPS (Barometric Pressure Sensor) that is identical to the MAP sensor, save for the vacuum line. If you’re ever going to switch over to mass air, you can use this existing sensor by simply capping the vacuum line and letting the MAP sensor open to the atmosphere.


9-Blade Fan (optional)


HO Fan

Technically you can reuse the stock 7-blade fan and fan clutch, as they should be just fine to handle the demands of an HO engine—provided they’re in good shape. While the HO fan’s 9 blades could help a bit, they’re not mandatory. Still, check that your fan and fan clutch are in good working order. If they need replaced, it’s perfectly fine to use the HO-spec replacements if you wish.





After all the parts are installed, you will need to reroute the spark plug wires to match the HO firing order (1-3-7-2-6-5-4-8). You will NOT need to change any fuel injector wiring in your stock harness for this conversion, no matter what anyone else tells you!

You can reuse your existing EVP, EGR valve, idle bypass valve, and radiator, as they’ll be adequate enough for the HO conversion.

Stock timing is still 10 degrees BTDC. Once the car is running correctly, you can get some added power if you bump up the timing to 12 or 14 degrees. Try 1-degree increments at a time since every engine responds differently, but back off if you hear any detonation (pinging). Also remember that if you do advance the timing, premium unleaded gasoline (93 octane or higher) is REQUIRED.

As with any engine build, be sure to properly check the piston-to-valve clearance. Almost any other high-performance camshaft will REQUIRE performance dished pistons! Unfortunately, the removal and replacement of your stock flat-top pistons will have to be done with the engine outside of the car, on an engine stand. You could also consider having them fly-cut. So please consider this if you’re debating on putting better pistons in your motor. In general, if you think the 225-hp version of your engine will be adequate, then the stock pistons will work great. But if you plan on adding a supercharger, nitrous oxide, or even a healthier camshaft, you will have no choice but to pull the motor out to change the pistons.

Don’t forget that after the conversion (or even during), you must upgrade to dual exhaust to get the full 225hp benefit. Reusing the stock cast-iron manifolds and single exhaust will result in slight bogging and decreased power output.

5.0L V8 - Standard-to-Mid Output Conversion


If you’re thinking about doing the HO conversion later on and have parts accumulated, you may be tempted to throw them on now. Or if you don’t want to do the full HO conversion but would like a little more power, you might be looking for a way to do that. This section is designed for you.

You must first realize that the very heart of the HO motor vs. your stock 5.0 is the camshaft. Without the HO cam, you don’t have an HO motor. Although the HO cam runs short on upper-RPM power, it’s still miles above our stock cam. However, the HO cam requires a lot of other components and things to make it work correctly: the computer, firing order, larger fuel injectors, and MAP sensor. This being said, there are things you can do to make more power out of your stock 5.0 without changing all those things. A few of them are listed below, and all are parts that you would need for the full HO conversion anyway. The horsepower estimate, after all components below are installed, would be in the neighborhood of 190-200hp.


HO E7TE / Aftermarket Cylinder Heads

The stock 1986-88 Cougar heads are, to say the least, very restrictive. Narrow inlets and “high swirl” exhaust ports add to fuel economy, but at the expense of good power. These heads were also used on the ’86-’88 Thunderbird, the ’86-’91 Crown Victoria/Grand Marquis, and the ’86 Mustang GT. In ’87, the Mustang received the F-150 truck heads (a.k.a. the E7TE-AA castings); the Cougars still had the restrictive heads through 1988. This is the most obvious point to start. You will gain approximately 15hp over the stock heads and experience much better upper-rpm power. You can drop these heads on anytime you wish. With the stock E7TE heads, you will reuse your pushrods and rocker arms. GT-40 heads and Trick Flow heads, among many others, can also be used, according to your budget. Also, should you wish to port and polish your new heads, or install stock-ratio 1.6 roller rockers, you can do that with no ill effects from the standard output camshaft.


HO/Aftermarket Upper Intake Manifold

There is a minor difference in casting between the non-HO and HO plenums, the difference being a larger inlet for a few more horsepower. The stock Mustang upper has the letters “HO” stamped under the removable top plate. If you decide to go with this intake, you should install the matching EGR plate and EGR valve from the Mustang as well; this will give you maximum airflow performance. By the way, the non-HO and HO lower intake manifolds are all the same. If you are thinking about getting your intakes Extrude-Honed, the Mustang HO upper is an excellent (and stealthy) choice, flowing nearly as well as a GT-40 intake after honing.

Another option is an aftermarket upper and lower intake combo. Your choices are limitless now: Cobra, GT-40, Edelbrock, Trick Flow, Holley, etc. It all depends upon your budget, but keep in mind that your engine is a fancy air pump. Too much airflow with the stock speed density computer may bog down the motor upon acceleration. Also, a heat (phenolic) spacer is a popular item and is worth looking into if you’re so inclined.


HO/Aftermarket Throttle Body

The stock Cougar/Thunderbird throttle body is a rather restrictive 50mm. The stock Mustang throttle body is better at 60mm. Your stock one will work if you can’t get the bigger one, but your car may hesitate slightly upon acceleration due to restricted airflow.

If you’re shopping new, a 65mm aftermarket unit will still work with the stock speed density computer and give you much improved airflow. Anything over a 65mm throttle body on a stock motor will decrease low-end torque and actually bog down the motor with too much air. These bigger units should be limited to severely modified motors only. Also, be sure to buy a throttle body made for 1987-up Mustangs—the 1986 throttle bodies were unique. And remember to get a throttle position sensor (TPS) to match the new throttle body, as your stock one may not work.

5.0L V8 HO Transplant


There’s sometimes a point when, as much as you love your Cougar, you might be pining for more power. Maybe the stock 5.0 is shot and you need a new motor anyway. Or perhaps you have the underpowered 3.8 V6 under the hood right now. Considering the availability of the HO 5.0 from wrecked Mustangs, it sure seems logical to put that engine under the hood of your Cat. This section will tell you how to drop in the venerable High Output Ford 302 into your Cougar, whether you currently have a V8 under the hood or not.


5.0L HO Engine

There were relatively few Ford Motor Company vehicles from our era that received the factory HO 5.0 motor. Now there’s plenty of information out there about these cars, but in general here’s what you need to know to make your life simpler for this swap.



The 1986 Mustang/Capri 5.0 is different from all succeeding years; it actually has a lot in common with our factory 1986-88 engines. In fact the only differences were the camshaft, fuel injectors, factory headers and the EEC-IV computer. This factory-rated 200 hp engine would make a decent starting point, although you’d probably want to consider an upgraded HO conversion while the motor is out. The pistons are aluminum flat-tops. (The Capri was dropped by Mercury after 1986).



Starting in 1987, the Mustang went to the legendary 225 hp version that we all know and love, with improved heads and camshaft. The Mark VII got this same treatment starting in 1988. These initial HO engines were of the speed density variety. Internals were beefed up and the E7TE casting heads were a big step up from the 1986 HO engine. Pistons were now of the TRW forged variety.



Beginning in 1989 (technically 1988 in California) the Mustang went to the mass air setup. (The Mark VII never received factory mass air and was discontinued after 1992). The motors themselves didn’t really change but the engine harness, ECU and some related sensors were updated. The 1993 HO engine received hypereutectic pistons, which are good for daily use but will not hold up to forced air induction or nitrous oxide. Also, a revised horsepower rating method employed internally at Ford reduced the HO 5.0 down to 205 hp; in reality none of the components changed, and most Fox enthusiasts still refer to it as a 225 hp engine.

Concurrently, the Cougar and Thunderbird received an HO 5.0 from 1991-93, rated at 200 hp. It was a different version than that used in the Fox Mustang. Physically the blocks and most of the internals resembled the 1993 engine, but there was a different camshaft grind. All of the accessories and brackets were also revised to hug the block for better NVH. The most important change was the dramatically lowered upper intake manifold, designed to clear the low MN12 hood, and the curved intake attachment for the throttle body.



In 1994 the all-new SN95 Mustang debuted and with it was a revised HO 5.0 engine, rated at 210 hp. Virtually all the parts needed to stuff the motor in the engine bay were already pre-engineered for use in the 1991-93 MN12 Cougar/Thunderbird, so Ford wisely used that engine setup for the SN95 Pony. This lasted until the end of 1995, and with the debut of the 4.6L SOHC engine in 1996, the HO 5.0 was history in Ford cars.



However, the 5.0 HO engine did live on in the Ford Explorer and the Mercury Mountaineer. Again, new brackets and accessories were necessitated due to the Explorer’s tight engine bay space. Radical new curved manifolds (and later, headers) were designed to clear the massive engine crossmember, and a new oil pan did the same. Most people know this engine for its new exclusive intake manifold setup, again lower and now less restrictive, outflowing even the aftermarket Cobra intake package. Rated at 215 hp, this engine is the newest factory 5.0 HO available and, due to its rugged nature, is one of the more desirable ones.

Even though there were quite a few vehicles to sport the HO 5.0 from 1986-2001, not all of them are optimized for your particular engine bay or engine management system. Generally the easiest to swap would be 1986-93 Mustang engines, and 1988-92 Mark VII engines. It is a little difficult to get a 1994-95 Mustang engine setup to work in our cars; ditto for the MN12 engines. The Explorer/Mountaineer engines need downgraded to Fox accessories and brackets. The wiring and computer to run the 5.0 is different between cars and body styles…fortunately part of that problem can be resolved using a harness from our own cars.

Now you must realize that no two Cougar engine bays are alike. So a 1985 5.0 and a 1987 3.8 V6 have much different engine bays, as far as the configuration goes. The key to having this whole transplant work smoothly is realizing how the 5.0 engine bay looks. Any 5.0 engine bay from any Fox automobile from 1986-on (including Mark VII, rear-drive Continental, Capri, and of course the ‘Stang) is arranged in the same basic way: battery tray and starter solenoid on the driver’s side, throttle body and air cleaner box on the passenger side. Your engine bay MUST be configured to this arrangement for the HO 5.0 to fit. Now just because your engine bay doesn’t look like this now, doesn’t mean you can’t make it that way. As long as you get the necessary components from the donor car or another Cougar, you will be assured that the 5.0 will fit and work properly.


The following will help get you generally oriented with what you’ll need for the swap:

Turbo Cars (1984-86 Cougar XR7, 1983-86 Thunderbird Turbo Coupe)
If you have a 1984-86 XR7 (or Turbo Coupe) your engine bay is already configured for the new HO 5.0 motor. The 1984-85 cars must either cut a hole in the passenger side inner fender for the air cleaner assembly so fresh air can get in, or use a K&N Filtercharger to get around that. Your vacuum tee can be reused, if you wish, and the battery tray is just fine.

1986-88 Factory 5.0 Cougars/Thunderbirds
You’re all set.

1988 3.8L V6 Cougars/Thunderbirds
Your engine bay is already set up for the new motor. You will need to replace sensors on the firewall; the stock vacuum tee can be reused.

1983-85 5.0L V8 Cougars/Thunderbirds, and 1983-87 3.8L V6 Cougars/Thunderbirds
Your engine bay is completely opposite of what’s needed, which means you will have to do some additional work. It’s not bad, really; it just requires a little more time and a few more parts. Your current engine crossmember (aka “K” member) will not have to be changed. You’ll just need the appropriate V8 motor mounts (see below).


The 5.0L HO V8 Engine


There are actually quite a few differences between our stock SO (standard output) motors and the HO (high output) motor. Below are the major differences:

1987-95 HO 5.0 (Mustang / Mark VII)
Non-HO 5.0 (Cougar / Thunderbird / Crown Vic / Grand Marquis)
Higher-flowing E7TE heads
Standard “swirl port” heads
Higher-lift HO cam (performance/fuel econony)
Lower-lift cam (fuel economy/torque/towing)
TRW forged pistons with reliefs*
Aluminum flat-top pistons
60mm throttle body stock
50mm throttle body stock
19 lb/hr fuel injectors
14 lb/hr fuel injectors
Better breathing upper intake
Standard flow rate upper intake
9-blade fan
7-blade fan
Factory unequal-length headers
Factory cast iron exhaust manifolds
HO/351 W firing order
Unique non-HO firing order
225 hp**
150 hp (155hp in 1988 only, w/dual exhaust)

* 1993-95 HO 5.0’s have hypereutectic pistons from the factory.

** 1993-95 HO 5.0’s were rated at 205-215 hp using Ford’s revised HP rating system. The output is still approximately the same as the pre-1993 HO engines.

In short, the HO has all the good stuff. Not that the stock non-HO motor is bad; it’s just not as good as the HO engine.



If you live where salvage yards are plentiful, a stock HO 5.0 shouldn’t be that hard to find. Finding one that hasn’t been beat to death, on the other hand, is a whole different story. If you luck out and find the motor still in the car then you can pretty much judge by the car’s condition how the engine will run. And remember this: some salvage yards will sell you anything just to make a buck. Buyer beware. Be sure you’re dealing with reputable people, first of all, and then see what kind of warranty there is on the motor. If there is no warranty offered then shop somewhere else. Also, be sure to ask if there is a core charge. That means you get charged extra until you bring your old motor back, when they refund you the fee. It’s more money up front, so plan on that. If you cannot find any where you are, there are lots of places online to shop. If you’re building a 302 from scratch, Summit Racing still carries bare 5.0 blocks that are already set up for roller lifters.



This is practically anyone’s guess but whatever you do, don’t get overanxious about finding one for a good price. If you’re patient enough you will find one, even if it means spending an extra $100-$200 US for one you know is better. Mileage is a concern; obviously, $500 for a motor with over 100,000 miles is not a good deal. We suggest trying to find one with the lowest possible mileage for the lowest possible price. Sometimes that’s not easy and you’ll need to compromise.



Very generally, a 3.8L V6 and 5.0L V8 automatic transmission from these cars can interchange, as most internal specs are the same and they both have the same small-block Ford bolt pattern. This includes the C5 (3-speed) and AOD (4-speed overdrive). Technically they can be used with an HO 5.0 but the converters will have a lower stall speed, which shouldn’t really hamper performance too much but may lead to a slight drop in power output. A rebuild may want to be considered, as well as a shift kit and higher-stall converter. You could also consider using a Mustang HO AOD or even a performance AOD. The existing throttle valve (kickdown) cable can be reused if you’re keeping the same transmission with the HO motor. For linkage, see below. If you’re swapping over to a 5-speed you can use all Fox Mustang parts.



Yes, if you’re going from a V6 or I-4 to the V8. You will need at least Cougar/T-Bird 5.0 front springs. Rear springs can be used from V8 cars as well, or you can use cargo coils (heavy duty variable rate). You can safely use any front and rear springs from any 1983-88 Cougar/Thunderbird V8; they will all fit and return a compliant ride with the new engine. You should consider installing at least the V8 rear sway bar from a Mustang/Turbo Coupe/XR7. The front sway bar would be optional but it does help a bit.



This is a touchy situation as there were multiple kinds of fuel pumps used in these cars over six model years. Some earlier cars had two pumps (one in the tank, one on the framerail), some had one (in the tank). The HO motor in the Mustang and Mark VII were rated at 88lph (liters per hour) from the factory. No Fox Cougar or T-Bird had a factory fuel pump with a rating that high; ours were just 65lph at best. It is highly suggested that, someway, somehow, you upgrade the fuel pump to one with a rating of at least 155lph. For those people with the single factory pump you can simply use a good quality aftermarket fuel pump (BBK, Walbro, etc.). Avoid parts store pumps as they tend to have a high failure rate. You will only need the pump itself, not the hanger, and you can reuse your sock. Now for those of you that have two pumps it might be worth your while to change your fuel tank over to one from a one-pump car, and run some new fuel lines. That is certainly the easiest solution to bypass the second pump although it does require more initial expense.



Besides the engine itself, you will need quite a few more things. Assuming that you do not already have a 1986-88 factory 5.0 under your hood and that you’re staying with a computer-controlled engine with an HO 5.0 computer, first and foremost you will need 5.0 wiring harnesses. For Fox cars there are three harnesses: the main EEC harness coming from the computer inside the passenger compartment and out through the firewall to the motor; a separate fuel injector harness that plugs into the main EEC harness; and a separate oxygen (O2) sensor harness that also plugs into the main EEC harness. You will need all three harnesses. It is highly recommended that you use a 1986-88 Cougar/Thunderbird 5.0 harness, regardless of computer style (speed density or mass air) and even though it was never HO-style in nature. This is because the main harness will mate up to your existing dash harnesses better than, say, a Mustang or Mark VII harness. Although those could be used they would need repinned in a few places. The 1994-95 Mustang 5.0 and 1991-93 Cougar/T-Bird 5.0 harnesses are generally incompatible with Fox cars and should be avoided. The 1986-88 Cougar/T-Bird 5.0 harness generally will not need repinning (unless mass air is used). Of course, this all depends upon the model year of your car and your dash style.

There may also be a need to change the harness on the driver’s side of the engine bay. This harness couples behind the dash and extends outward for some engine controls, such as the alternator harness, fusible links for the starter solenoid, and so on. They also contain the wires needed for the headlights, side markers, turn signals, windshield wiper motor, and other accessories. This is probably the trickiest part of the swap, as what you have now may not mate up with the SEFI 5.0 engine. It’s possible that it will…but also possible that it’s not.

You must also get a compatible EEC-IV computer module to use with your motor. You will not be able to reuse your stock one. Each Ford EEC processor has a calibration code printed on top, usually 3 characters long. For speed density, a computer marked with DA1 or DB1 (1987-88 Mustang) will work. You could also use a 1988-92 Mark VII computer (DX3, DY3, VL2, D9S) although you will be speed limited to 105mph with most of them. For mass air, the ever-popular A9L (manual) or A9P (automatic) are the computers of choice. Most of these computers are easily available on eBay if you can’t find one at the salvage yard, but you can also get remanufactured computers at parts stores (though we hear the quality is hit-or-miss so buyer beware). Don’t forget to also strip the firewall of all related sensors, wiring, and vacuum lines from the donor car.

Next, you will need all the brackets and accessories for the motor as well. This is due to the serpentine belt configuration. If you’re replacing a stock 5.0, you can reuse your old accessories and brackets if you wish. But technically, the brackets and pumps should come with the motor. The stock Mustang metal fuel lines on the motor will also be necessary; if unavailable, use them from a 1986-88 Cougar/Thunderbird 5.0. The radiators used in 3.8 and 5.0 cars will be adequate enough for the new 5.0; owners of 2.3 4-cylinder turbo cars are strongly urged to buy a new radiator made for a 5.0. You can reuse your stock 7-blade fan and fan clutch, but can upgrade to the HO 9-blade fan if you wish.

As far as motor mounts for the new engine, you have to be careful. You can use Fox Mustang-style mounts in 1983-85 Cougars ONLY. This is because the Cougar’s engine crossmember (a.k.a. K-member) was very similar, if not identical, to the Mustang. Beginning in 1986, the Cougar got its own special K-member (which may have also been shared with the Mark VII). So that means you’ll have to get motor mounts for a 1986-88 Cougar 5.0, which is not easy. Fortunately there is a Fox Cougar/T-Bird enthusiast that is manufacturing high quality motor mounts for our cars; see this website for more information and ordering.

If your Cougar is not a 1986-88 5.0 car to begin with, you will also need the following from a 1986-88 Cougar/Thunderbird 5.0 ONLY:

  • Battery tray
  • Starter solenoid and ignition coil.
  • MAP sensor (firewall).
  • A/C lines (stock condenser will work fine. Stock accumulator may work fine, depending upon the model year).
  • TAB/TAD sensors (located in the rear passenger side of the engine compartment, behind the strut tower)
  • Air cleaner box and tube(s)



After removal of the old engine and before installation of the new engine can begin, you’ll have to do a little more work with the motor out first. You will need to install the main EEC harness. Be aware that the hole in your car may be oval, and some harnesses are more square (and vice versa), so there may be some trimming or covering up at the EEC harness hole in the engine bay. Also, you can install the new computer inside the passenger compartment footwell and hook the wiring to it. The injector and O2 harnesses will have to be installed after the motor is in. You can simply flop the new harness onto the windshield to keep it safe and out of the way.

Next up are the TAD/TAB sensors, behind the passenger side strut tower. These control the EGR/EVP. Parts from a Mustang are not quite exactly like those on the Cougar/T-Bird 5.0’s; however, they can be made to work. Mark VII sensors require more work to use correctly as the harnesses may be different. After those are all in, you can install the battery tray on the driver’s side. Everything else (starter solenoid, ignition coil, air cleaner assembly) will have to wait until the new motor is in.

Once you’ve got the motor in, bolted down, the transmission installed and the transmission crossmember back in, you can start to bolt everything to the motor. We would highly suggest getting the wiring situation resolved first because it’s the most tedious. The most important thing to remember is that each sensor or connection has its own unique configuration, and can only reach so far, so that means you really can’t hook the wrong wires to the wrong sensor. Once all that is over with you can install the ignition coil first. It goes on the driver’s side strut tower toward the front. You should have some holes in the area so just bolt the bracket down and you’re set. You can also install the starter solenoid, almost directly above the coil, but on the side fender. On the other side, you can install the air cleaner assembly now, including the mass air meter if applicable. If your car did not have a factory hole in the front passenger apron (1983-85) then you’ll either need to cut one using the 1985-88 air cleaner box as a guide, or run an open-element air filter such as a K&N or similar filter. A mass air meter will require additional wiring that should be installed at this point.

For the exhaust system, it’s totally up to you, but we would suggest a full dual exhaust conversion since the HO motor was made for duals. Using the stock Cougar exhaust with cast iron manifolds is pretty restrictive and will result in a power loss and slight bogging on acceleration. See the Dual Exhaust Conversion section for more info.

If you need to adapt your fuel lines Ford makes a nice kit (p/n N803431-S) that makes life easy for you. It’s two unions and 4 clamps, used to convert your existing lines over. Cost for the kit is around $10. If you find your car cannot use this kit, you may have no other choice but to run all new fuel lines from the tank to the engine.

Now for the throttle and transmission linkage. If your old transmission linkage was rod-activated, you’re going to have to buy a TV (throttle valve/kickdown) cable, because the stock HO 5.0 throttle plate won’t accept a rod system. And your cable may or may not work, depending upon the transmission. Same may be true for your throttle linkage as well; there may be a new cable in your future. You may be able to use a ball-type connector from a Holley carb, sold at parts stores, to adapt your cable. Fortunately both cables are pretty inexpensive and easy enough to install.

Of course, these are the major sticking points for the conversion. There will be many small things that need addressed but you’ll figure things out. When all this is taken care of, hook the battery up, and turn the key. You should hear the sweet, sweet sound of a rumbling small block Ford. Yes, you have finally done it. Now go enjoy the fruits of your labor.



Don’t forget to now use the HO firing order (1-3-7-2-6-5-4-8).

Stock timing on the HO 5.0 is 10 degrees BTDC. Once the car is running correctly, you can get some added power if you bump up the timing to 12 or 14 degrees. Try 1-degree increments at a time since every engine responds differently, but back off if you hear any detonation (pinging). Also remember that if you do advance the timing, premium unleaded gasoline (93 octane or higher) is REQUIRED.

5.0L V8 - Mass Air Conversion


NOTE: This section is for converted or transplanted 1987-88 HO 5.0 motors ONLY. It is not intended for the stock Cougar/Thunderbird 5.0 motor. Any attempt to convert a stock non-HO motor to mass air can result in serious damage to the engine.


The stock ’86-’88 HO engine from a Mustang has a speed-density computer setup. It’s good for inferring relative air intake, but it’s inflexible as far as adding high performance components, such as a healthier camshaft. The best you can do with speed density is a bigger throttle body and a K&N air filter, some exhaust work…and that’s about it. Ford began using the mass air system on 5.0 Mustangs beginning in 1988 (California only), and then it was added to all V8 Mustangs from 1989-1995, as well as HO Thunderbirds/Cougars from 1991-93.

Mass air is a more accurate way to measure airflow; the net result is better response and performance. In addition, the mass air computer is a “learning” computer, which means you can add a new component, and within a minute of starting up the car, the computer will automatically recalibrate itself around that item. As far as horsepower and mass air: the wallet’s the limit! But first you need to get the mass air setup in your Cougar. You can usually find the parts needed at your local salvage yard, or swap meets, or online.


Parts Acquisition


You will need the following items from a 1989-1993 Mustang HO 5.0:

  • Mass Air Wiring Harness Adapter
  • Mass Air Meter (with bracket)
  • Air Inlet Tubes (both)
  • Mass Air Computer


Mass Air Wiring Harness Adapter


Mass Air Conversion Harness

Mass air requires a few extra wires running from the mass air meter to the EEC-IV computer. The easiest solution for your wiring is to reuse your existing, working 5.0 harness and add a mass air adapter kit to your harness. These kits are available in the aftermarket from companies such as Interactive Systems and Technologies, as well as others, and sometimes even on eBay. Basically it’s a 4-wire hookup for the mass air sensor, and it runs from the sensor through the firewall, tapping into the main computer harness. It’s very neat and efficient since you don’t have to either purchase a new harness or take out your existing one. Plus, it’s relatively inexpensive.

You may be asking, “Why not just change out the whole harness to one used in a mass-air equipped Mustang?” The reality is that the Mustang EEC harness is not fully plug-and-play compatible with your Cougar’s existing internal wiring. For example, the 1990-93 Mustang 5.0 harness is its own beast, since those were the years that the previous-generation Mustang had a driver’s side airbag, and it can create difficulties when installed (such as the fuel pump not getting power). Even a 1989 Mustang HO wiring harness, which should be a little more compatible, needs several wires repinned. It’s not that these harnesses cannot be used at all; it’s just that they’re simply not easy to use. Several people have done it, mostly for the sake of aesthetics, but it required multiple shop manuals and some time to work out issues. In this respect the 4-wire mass air add-on kit is easier, cheaper, and much more efficient.

Mass Air Meter


Mass Air Meter

The mass air meter itself is coupled inside the air inlet tube, and it measures the air coming into the engine. It’s the heart of the mass air operation. The sensor on top has a two-fold job: one “hot” wire inside measures air volume, while the “cool” wire measures relative air temperature. In other words, it’s a very sensitive piece and should never be touched with bare skin or any metallic objects. The sensor is calibrated to your corresponding fuel injectors. So if you’re running stock HO orange 19 lb/hr injectors, the mass air sensor must match those. It is possible to remove the sensor and replace it with another sensor—for example, in the future if you’re upgrading to 24 lb/hr injectors, you can keep the meter and just swap out a 24 lb/hr calibrated sensor.


Mass Air Meter

The stock Mustang mass air meter is restrictive in diameter at 60mm and has the internal air vane which restricts airflow; a different mass air meter will allow for better breathing. Most people shoot for a 70-75mm unit. Ford did make some factory mass air meters larger—for example, the supercharged V6 cars (T-Bird SC, 1989-90 XR7) had 70mm mass air meters from the factory. Swapping out the top would be an easy task. But really, if you have the cash, an aftermarket mass air meter is the way to go. They are usually much lighter, stronger, and less restrictive than a stock Ford meter.


Mass Air Bracket

The mass air meter is attached to a bracket that mounts onto the passenger side strut tower; you may have to drill new holes to mount the bracket but 1986-88 cars should already have the holes. Do not attempt to use the sensor without the bracket, unless you are using a lightweight aftermarket plastic meter or a metal cold air intake system that can support the mass air meter properly (see below). By the way, the sensor on the top is removable in case you ever need to replace it. It’s usually held on by a pair of safety Torx bolts. Be careful to never touch the electrode ends with your skin or any foreign material, as that can effectively kill the sensor completely. Always use mass air sensor spray cleaner to keep it clean; do not use carburetor cleaner.

Air Inlet Tubes


Mass Air Tubes

At first, these may not seem important; with speed density, you can run around all day without the air tube on with no side effects, save for all the dirt you let in. But mass air is a closed system; if you try running without these tubes, your car won’t even idle right, much less run at all. They are now two short tubes instead of your usual one. Installation is exactly how you think it is—pretty simple. You will reuse your existing air cleaner box, or if you’ve installed a K&N Filtercharger kit, that will not be affected. If you wish to use aftermarket metal cold air intake tubes (such as those made by BBK, MAC and others), feel free to do so. They’re going to give you more power due to the smooth inner walls and slight Venturi effect.

Mass Air Computer


EEC-IV Processor

You will need to replace your existing computer with the new mass air EEC-IV processor. There has been a lot of discussion on the Internet about which computer to use with which transmission. In the real world, it seems to be perfectly fine to use a manual transmission with an automatic; we’ve never seen any issues firsthand. However, some people say you can use either computer with a 5-speed, and not vice-versa. You will have to judge which computer will be best for you, but if you’re uncertain then stick to the computer which matches your existing transmission type.


Whichever computer you decide to use, there will be a calibration code on the sticker on the outside of the grey harness connector. You will need to keep this code handy for future reference, in case you need to purchase things like a BPS or new injector.


The following part numbers are for common Mustang mass-air EEC-IV computers with stock 19 lb/hr fuel injectors:

Automatic Cars (Calibration code A9P):

Manual Cars (Calibration code A9L):

Universal Rebuilt:




NOTE: Disconnect the battery before attempting any of the following!

The physical addition of the meter, bracket and air tubes is fairly easy and straightforward. The hardest part of the job is running the new wiring, and then pinning it into your stock harness. There are a few ways you can run the wiring. Inside the engine bay you can find a grommet on the firewall over on the passenger side and put the 4 wires through there. You could technically also drill a new hole and put a new grommet in, although you need to be careful when doing that. An alternative solution is to run the wiring inside the inner fender. With the car safely in the air, remove the wheel well liner and insulation and you will have clear access to run the wiring along the top of the fender support brace, and down into the area between the fender and the door. There is a second, empty hole beneath the antenna hole through which you can easily run the wires (note: if you have a power antenna you cannot see this hole and will need to remove the antenna housing to get to it). This puts the new wires exactly near the EEC-IV processor where you need them.

For wiring the mass air harness into the EEC harness, follow the instructions that come in the wiring kit. You will need to piggyback two wires onto existing wires, and place two other wires into empty slots in the EEC harness. In general:

Wire Color
Position in EEC Harness
Main Power (12v+)
Splice into wire at pin 37 or 57
Main Ground (12v-)
Splice into wire at pin 40 or 60
MAF Signal Ground
Place in pin 9
MAF Signal
Place in pin 50

The brown and blue wires will need to be cut to fit, and new terminals crimped onto the ends. It’s highly recommended that they also be soldered. For the red and black wires be sure to use either a high-quality splice connector, or to solder onto the skinned wire. Make sure all connections are taped up or covered securely and safely.

Now the mass air computer also requires that you reroute 2 wires in your existing main EEC wiring harness. These wires go to the TAB/TAD sensors, which control the opening and closing of the Thermactor air system, driven by the air pump. If the system does not operate correctly (in other words, if you do not change these wires around) you may experience hesitation, bogging and increased emissions.


There are 60 pin locations in the stock EEC-IV computer harness. You need to switch #51 to position #38, and #11 to position #32.

EEC-IV Pinout

You may also need to run a new wire to the fuel pump relay. In the Mustang, there is a secondary fuel pump monitor wire that runs from pin #19 on the computer to the fuel pump relay. It’s basically a double-check to make sure there is sufficient power running to the fuel pump. If you do not run the wire you will get a code 95 (secondary fuel pump failure) when an EEC-IV computer test is performed. It doesn’t mean your fuel pump isn’t running or working properly, just that the back-up check doesn’t acknowledge it. It’s up to you whether or not to run this wire. Again, follow the instructions that came with your mass air harness kit.

Also, some pre-1988 vehicles may need two additional wires run to the vehicle speed sensor (VSS) on the transmission. Most people do not but if you find that your vehicle performs poorly or throws strange computer codes, you may have to run these wires. Positions: pin 6 to the O/Y VSS ground wire, and pin 3 to the DG/W VSS power wire.

Your MAP sensor can be reused; just disconnect the vacuum hose, cap off the hose and you’re all set. Essentially that turns the MAP sensor into a BPS (barometric pressure sensor). If you experience idling or starting problems this could be due to the old MAP sensor being incompatible with the new mass air computer, which means you may have to get a new BPS from a mass air Mustang (1989-93). Some people need one, some don’t, but most of the time you’ll be able to reuse your existing one. Remember your calibration code when buying a new BPS.

Once the wiring situation is finished and all the other parts are installed, you can install the new mass-air A9L/A9P computer and reconnect the battery. If all goes well your car will start up as usual, and idle quality should be as normal. Now if the car doesn’t start at all you’ll need to double check your wiring, as mass air cars will not start without a correctly-wired mass air meter. Any rough idling may indicated a need for a new BPS sensor (see above), a bad mass air meter, or, again, possibly a wiring issue.

5.0L V8 - 3G Alternator Upgrade <b>NEW</b>


Thanks to Andrew for contributing this article.

3G Wiring Upgrade

One of the “must have” modifications for your foxbody Cougar/Thunderbird is improving the charging system and replacing the factory alternator with a newer 3G alternator that can help support electric fans, electric water pumps or things like sound systems.

Your Fox Cougar/Thunderbird likely came from factory with a 65 amp 2G alternator and it’s wired (from factory) in kind of a detrimental fashion. The power is carried to the battery starting with the 3 prong connector and those two “big” black/orange wires merge into one and is run along the radiator support. The 3G modification fixes this lack of 80’s engineering judgment (read: Kirchhoff’s law) with a larger battery cable (4GA recommended, 6GA minimum).


Parts Needed for the 3G Swap

  • 3G alternator (130amps) from a 1994-95 Mustang
  • 4GA battery cable (welding cable works fine), approx. 15ft
  • MegaFuse (175amp) holder and fuse (or marine-grade breaker)
  • Spade connector or proper connector from a 1994-95 Mustang
  • D-connector with 3 terminals (if you have an 86 or earlier)
  • Conversion kit or resistor for 1979-85 1G upgrades
  • (4) lugs for 4GA cable
  • Rubber boot for the alternator power terminal
  • Shrink tubing, electrical tape, zip-ties and wire loom

Standard Wiring for a 3G Swap

3G Wiring Upgrade

3G Wiring Upgrade

Wires illustrated below are ran in the stock location, wrapped and protected with loom as well as tied into place. A good location to install the breaker or fuse is on the frame rail under the battery.

1986-1988 Cougar/Thunderbird 5.0L:

3G Wiring Upgrade

The view beforehand.


3G Wiring Upgrade

The casing on a 3G alternator is rather large and it will require some slight modification to the alternator bracket in order to fit right. You will need to mark the bracket like so…


3G Wiring Upgrade

…then carefully cut the aluminum bracket. You can use a mini-saw, grinder, etc.


3G Wiring Upgrade

This is what the alternator looks like mounted. Area in red is the clearanced section for reference.


3G Wiring Upgrade

This is my routing for the wiring. You don’t necessarily have to do it this way but it is safe, accessible, and gives you room to work.


3G Wiring Upgrade

The underside view of the radiator core area with the wires in a loom and tied up out of the way.


3G Wiring Upgrade

Finished view of the 3G alternator installation.


Additional Info

Wiring a 3G Upgrade in a 1987-88 Cougar/Thunderbird
If you have those years, you can re-use the factory D-connector since it has 3 wires in it. Removing the wiring tape you will discover the white/black wire follows the harness and loops back to the rectifying connector (black connector with two black/orange wires)



2G Wiring Harness

You no longer require the black/orange wires and you can remove that entire harness which follows the radiator support to the starter solenoid, as that circuit is protected with a fusible link. Use a spade connector (or get a used proper connector from a 1995 Cougar/Thunderbird V6 AND Mustang V8 and V6) for the white stator wire.


2G-to-3G Harness

The only new wire you need to run is the 4GA battery cable from the alternator to a fuse box (or circuit breaker) and to the starter solenoid.

What it looks like installed below. Note: you should use a boot to cover the battery cable on the alternator to prevent potential unforeseen sparks in the future.

3G Wiring Upgrade


Wiring a 3G into a 1986 Mustang

Some models will only have 2 wires in the D-connector, missing the white “Stator” wire. Some 2G’s can be internally excited. You can get the connector at a salvage yard, alternator/starter repair shops or auto parts stores (Ford part is: WPT119). LMR also offers the 2G to 3G upgrade wiring kit. The factory harness looks like this:

3G Mustang Wiring Harness

You need to ditch all this and essentially connect the green and yellow wires to a new D-connector and use the new white (stator) wire to the Stator terminal in the 3G alternator.

3G Mustang Wiring Harness

1G to 3G Cougar/Thunderbird Upgrades (1980-85)

If you have an early Fox car, you will likely have a 65 amp 1G alternator and an external voltage regulator. The easiest method is to use a kit which is essentially “plug and play”. The instructions indicate to keep the existing power cable (black/orange), this is to power the factory amp gauge. It’s recommended to ensure that circuit is properly protected and functioning to help avoid the risk of fire.

An alternative method that also cleans up the wiring is to skip the wiring kits (like the PA or SVE kits). All you need to do is install the 4GA wire as you would normally do but you need to find a fused power source for the yellow wire and an ignition power source with a 440k 1/2 watt resistor. Below ignores the amp gauge and gives you an excuse to get a new volt gauge.

3G Wiring Upgrade


3G to 6G Alternators

The small case 6G from a 2001 V6 Mustang should fit your Fox body as it has mounting bolts 180 degrees from each other. The 6G has better bearings and cooling and looks a little different than the defacto 3G upgrade. The smaller case on the 6G means you won’t need to trim the alternator bracket.

Wiring the 6G is about the same minus the white “stator” wire, that is now internal and no longer needed in the harness. You’ll need a new connector or used one from a salvage yard.


Upgrade Kits

Here are some examples of upgrade kits available through LMR and others:

3G Upgrade Kit


3G Upgrade Kit

2.3L I-4 - Denso A/C Conversion <b>NEW</b>


Thanks to Kris for contributing this article.

“This Denso conversion was done on a 11/84 build Thunderbird. My goal was to get rid of the HR980 compressor setup and into something that will run the newer R-134a refrigerant. This conversion uses the factory A/C compressor from a 1991-93 Mustang with a 2.3L I-4.

“First things first: I swapped in a serpentine belt using the driver side brackets and all of the pulleys from a 1987-88 Thunderbird Turbo Coupe. The A/C bracket was sourced from a 1991-93 Mustang with a 2.3L. I have not touched the A/C pulley.”

  • UAC HA10018C A/C accumulator with hose assembly
  • UAC CN3554PFC for the parallel flow
  • UAC HA9140C liquid line assy w/ FOT

“The accumulator hose assembly needs to be modified to reach the compressor. The angle is also off going to the condenser. I took it to my local A/C shop and they used the parts from that new assembly and built what’s pictured.

Denso 2.3L A/C Conversion

Denso 2.3L A/C Conversion

“The parallel flow almost fits but you need to clearance the core support a little to clear the hard lines coming off the PFC. It’s also a little ‘short’…essentially you will just drill out the rivets and move the bottom brackets down ONE hole and rivet it in place again. TEST FIT your condenser first before going this route….you may not have to do that. I had to clearance the bracket by the hard line so it wouldn’t rub, that was simple enough.

“Once the condenser is in make sure none of the hard lines rub on your core support. I had to grind some of the support out so it didn’t rub and cause heartache later.

“The liquid line could honestly be used from a Turbo Coupe or Mustang. I used the one from a 1993 mustang, the only difference was the connection into the EVAP. Older cars screw into the EVAP and the newer ones use a quick disconnect…when they changed that I could not answer that at this time. I had my a/c shop fix that for me.

“When I started connecting hoses to the condenser I found the O-rings that came on it were just a little too big, I went to a size close to that but OD was a little smaller, no sealing issues as of yet.

“I had to get fancy with a pick to get the spring clip over the liquid line…it was a royal pain but I finally got it….took a few beers.

Denso 2.3L A/C Conversion

“Top hose went in with mostly no problem. This condenser uses 3 o rings on the fittings. I took the very front one off and left the 2 back ones on (the OEM condenser was the same way from factory so why not). This allowed me to finally click the top hose into place.

“The system was sitting under vacuum and held for at least 10 hours.”

He later wrote:

“System has been working great with no issues right now!

“I got all that stuff (hose assembly and accumulator) from a ’93 Mustang with a 2.3. I think the issue that I was having is because I have the FMS intercooler kit for the 1983-85 Cougar/T-Bird. So I went the route of getting custom hoses. Perhaps if I didn’t have that stuff in the way or kept my car non-intercooled it would have fit without issue. I’ve heard claims that it works but I’ve not seen any proof.”

TBI-to-Carb Conversion


Because the 1980’s was an era of sweeping change as far as automotive electronics, our cars were caught smack dab in the middle of those changes at Ford. At the beginning of the decade, carburetors were still the norm; then we went through the transition phase (central fuel injection, or CFI); and finally by the end of the decade, sequential fuel injection (SEFI) became standard. The good news is, major objectives such as improved fuel economy and better emissions controls were achieved. The bad news is that horsepower did not significantly increase, a problem when the cars’ weight also increases. If you own a 1983-87 V6 or 1983-85 V8 Cougar, you know this firsthand. Plus, with three different types of fuel delivery in just the aero Fox Cougars alone, it can be daunting sometimes to understand and diganose problems. Certainly if you’re comfortable with a good old-fashioned carburetor, it would be nice to tune things that way.

If you’re looking to ditch the stock CFI unit and pop on a carburetor, this is a great way to get back some needed power. Yes, you’ll be bypassing some emissions controls but you can retain your EGR and PCV valve if that’s an issue. The key here is not only to unlock some horsepower but also to keep the car driving great while still being managable.

You need good cylinder heads to start with for a carb to work properly, and right now if you have a 1983-87 3.8L V6 or a 1983-85 5.0L V8, then you have them from the factory. There are better heads to use but for early-to-mid 1980’s castings, these are not bad at all.

The next step is finding a compatible lower intake manifold. Your stock intake (V6 or V8) will handle a 2-bbl carb just fine. On the 5.0L V8 side, if you want to throw on a 4-bbl carb, take your pick! A quick trip to Summit Racing or Jeg’s online will net you anything you wish. Or you can use a 1979-85 Mustang 5.0 carb-spec intake. For the 3.8L V6 you’ll need to hunt down the hard-to-find 3.8L carb intake, used in 1982-83 in the U.S. and up through 1984 in Canada.



Next you’ll need to find a carburetor. For a stock 5.0 with stock heads, anything over 600-650 cfms is going to be serious overkill. Really, if you’re not planning any exhaust work, you can get away with a 600 cfm carb easily. Again, aftermarket carbs are plentiful at the places mentioned above. For the 3.8L, once again you’ll need to hunt down 1982-83 parts.

Now the hard part: getting all the linkage set up and correct, installing a new distributor, tweaking the fuel delivery system, and installing the correct components for the ignition system. You will not be able to retain your EEC-IV components (1984-87) in the ignition system; you will have to revert back to the older but still usable Duraspark II system that Ford employed in the early 1980’s. For 1984 models, you have two fuel pumps: a high-pressure and a low-pressure pump. You can reuse the low-pressure pump for your needs. For all other years, you will need to either install an aftermarket low-pressure (carb) fuel pump inline, or use a mechanical fuel pump (which requires an older timing chain cover). More information on the fuel system and all other details below.

Tim has written the great article below on how to do everything right on his ’84 Thunderbird V8. Please note that some information is experimental, and some is from his opinion only. If you’re going to follow the instructions, you will do so at your own risk and cannot hold Tim or this site responsible. Please see our disclaimer for more details.

“With a little ingenuity you CAN convert your 5.0 from the TBI EEC system to a 4 barrel carburetor and Duraspark II ignition without losing ANY of your convenience features, such as cruise control, or the use of your AOD transmission.

“I converted my 1984 Thunderbird 5.0 using a non-EGR Edelbrock intake (model 2121), a vacuum operated Holley carburetor, and a distributor for a carbureted 5.0 Mustang. I got the ignition module from the local salvage yard. I also got a ballast resistor from the parts store (needs to be 0.8 – 1.6 ohms). Most aftermarket books showing the ignition systems should have a decent representation of the ignition wiring.

“I used the existing fuel lines, ignoring the return line and the purge line, since without the TBI and EEC, there is nothing to utilize or operate them. How you hook up the fuel line to the carb is your choice. You can use rigid steel line, or adapt everything and use flexible rubber fuel line. Finally, find a 12″ long 5/16” steel line with appropriate fittings and put it in place of your high pressure fuel pump. Then find the connector for the fuel pump relay in the right side kick panel near the computer and ground the tan wire. That will allow the low pressure fuel pump in the tank to operate full time. If you don’t, the computer will turn it off because it won’t sense any fuel usage.

“The only other issue is the TV rod for the AOD. After looking at the throttle Body setup, and talking to my local transmission guru, I determined that any mount point on the carburetors accelerator plate would be too close to the pivot point of the plate, reducing the travel distance of the TV rod. This was determined by trial and error, as my original connection was on the carburetors linkage plate, and the transmission wouldn’t shift properly. I don’t think I can give specific directions for this, so you must look at your original stuff and figure the best way to duplicate the linkage travel as best you can. I just fabricated an extension plate to mount the ball stud on, putting it out further from the pivot point, and that solved all my shift errors. Transmission works same as before, for which I’m pleased.

“Seems Edlebrock managed to include an adapter plate for the OEM throttle linkage bracket with their intake, model 2121, and with a slight tweak the original stuff mounted and fit nicely. Had to buy a set of ball studs for the throttle plate on the carb, a 600 cfm Holley vacuum secondary, then managed to put one in backwards for the AOD TV rod, reversing the grommet on the rod, which Holley said wouldn’t work. They didn’t design the throttle plate on the carb to work with the AOD tranny TV rod, but they told me the cable assembly used on the later models would work. Lokar makes one, and Windsor Fox makes a conversion kit, although theirs seems to require replacing the rod in the tranny, too. Not sure about Lokar’s cable kit yet.

“One note of importance about the ignition wiring – you must cut the tach wire to the ECA, since the EEC system distributor signals the computer to produce the tach signal, and the Duraspark II system produces the tach signal at the distributor. If you don’t disconnect the ECA from the tach signal, the tach signal from the Duraspark II distributor will be lost in the ECA, and the coil will never see it. Easiest way to do this is cut the tack wire just off the coil, and splice into it there for the ignition module.

“With a set of later model heads reworked for a nice top end overhaul, the Edlebrock intake and Holley carb, and the Mustang headers with dual exhaust all combined seem to have put me close to the 200hp range, because performance is way up.”

High Torque Starter Upgrade


Thanks to Ed for contributing this article.

In 1989 Ford began using a newer style starter called the Permanent Magnet Gear Reduction, or PMGR, starter. It weighs half as much as the old style starter that our cars came with: the old one is about 30 lbs., and this one is about 15! The new starter provides more torque and requires less power to operate. This upgrade is a win/win situation all around. The PMGR starter can be had purchased from your local salvage yard or from parts stores. Here’s a list of potential donor vehicles for the newer starter:


Vehicles that use the PMGR starter compatible with the 3.8L, 5.0L, and 5.8L:

  • (1996-92) Ford Bronco 4.9L, 5.0L, 5.8L w/ AT
  • (2002-92) Ford E Series 4.2L, 4.9L, 5.0L, 5.8L
  • (1998-92) Ford F Series 4.2L, 4.9L, 5.0L, 5.8L
  • (1991-90) Ford LTD Crown Victoria, Mercury Grand Marquis 5.0L
  • (2003-94) Ford Mustang 3.8L
  • (1995-92) Ford Mustang 5.0L
  • (1997-90) Ford Thunderbird 3.8L, 5.0L
  • (1992-90) Lincoln Mark VII 5.0L
  • (1990) Lincoln Town Car 5.0L
  • (1997-89) Mercury Cougar 3.8L, 5.0L

Vehicles that use the PMGR starter compatible with the 2.3L:

  • (1993-92) Ford Mustang 2.3L
  • (2002-91) Ford Ranger 2.3L, 2.5L
  • (1999-94) Mazda Pickup 2.3L, 2.5L

The old starter on the left; the new one on the right (these are for the 5.0L engine).

PMGR Starter


There is one wiring change that must be made for the new starter to work on your car. Here’s a picture of that change.

PMGR Starter

AOD Automatic Transmission Upgrades

The Ford AOD transmission from the 1980s isn’t known to be the strongest transmission. It was used in a wide variety of rear-drive Ford passenger cars and trucks throughout the decade, but it really never seemed to get better as time went on. The only exception seemed to be the heavily-strengthened internals for the 1989-93 Thunderbird Super Coupe and 1989-90 Cougar XR-7. The rest of Ford’s lineup got the “regular” version. Eventually the AOD was replaced with an electronically-controlled version with modified internals. So our AOD was really the last of its kind: all mechanical and hydraulic, no sensors, no electronics.

It’s not like the AOD is a rare thing…quite the contrary. There were millions of them installed in Ford vehicles for 15+ years, and you can still find them in salvage yards today. So parts are still plentiful and so are your options should you choose to beef one up.

Some of the details here are the same as what’s in the Transmission Help section, but we wanted to break out a dedicated page to the AOD to assist with modifying it for your purposes.


Transmission Cooler


Transmission Cooler

Adding an external transmission cooler will add greatly to the life of your AOD. If you tow, are in lots of stop-and-go traffic, do lots of highway driving, or idle quite a bit, then you likely need to get an additional cooler. Now from the factory, all automatics have a cooler that’s built into the side of the radiator. It’s a noble idea from the factory…in reality, though, it’s just adequate enough to keep the transmission cool. The new external cooler will bypass the cooler in the radiator, and will actually attach to the front of the a/c condenser. You will need to either adapt your stock transmission lines, or cut them and attach new ends, in order to get them hooked up to the new cooler. Adapting is much simpler and only requires a few new brass fittings. The advantage is that you can always go back to the radiator tank cooler if you need to. You can buy transmission coolers from almost any parts store. You won’t need anything really heavy duty; buy one for the minimum GVWR or the next one above that.


Shift Kit


AOD Shift Kit

The ubiquitous shift kit will firm up your shifts, prolong the life of the transmission, and give you slightly better gas mileage. Shift kits work better in conjunction with a higher stall torque converter but that’s not required. Most of these older-style mechanical transmissions (meaning those without the aid of electronics) can benefit from a shift kit. And you can tailor the kit to make the transmission shift to match your driving style—crisp, firm, or head-snapping. The trouble is, how do you know which kit to buy? In this area especially, you get what you pay for. Now we won’t be slamming any companies’ products here, but typically the lower-priced kits are going to give you more problems than the more expensive kits. The Baumann Engineering kit and the Trans-Go kit are both excellent and are highly recommended. If you decide to install the kit yourself, it’s about a 4-hour process and can be tricky if you’re not careful. When in doubt, have a professional do it for you.


Upgraded Internal Components

The most popular item to upgrade for the AOD is the Ford Racing wide ratio upgrade kit (M-7398-D), which is the same as those found in the 1989-93 Thunderbird Super Coupe. It’s not cheap but it’s a worthy upgrade.

Also, a single piece input shaft will provide greater strength than the stock two-piece unit. Again, it’s expensive but is a lot stronger.


Valve Body and Modifications

An aftermarket recalibrated valve body greatly improves the strength and performance of your AOD. For around US $500 or so, you can get a professionally built valve body that makes your AOD shift way better than new. There are many companies that offer these, such as Silverfox Performance Transmission, Performance Automatic, LenTech Automatics, and many more. Be sure to do your homework on these, and also figure for having it installed if you’re not willing to try it yourself, as this can be a pretty daunting job for the inexperienced.

There is also the “epoxy mod”, where AOD owners won’t have to fear about overdrive kicking in at wide open throttle. Third gear will be held so long as you hold the accelerator; letting off allows OD to kick in. It requires a drill bit and some epoxy; this is a free and time-tested mod that solves one of the annoying issues about a floor-shifted AOD transmission. You can find out more about this mod with a web search.


Torque Converter


AOD Torque Converter

The stock AOD torque converter stalls at approximately 1500-1800 rpms. This is okay, but for engines with moderate to heavy modifications, a higher stall torque convertor is a must. Usual ranges vary from 2000 rpms to 3500+ but you’ll need to talk to a transmission specialist to find out what stall speed is best for your car, as you need to select a converter to match the camshaft you’re using. Remember that when you raise the level of camshaft performance with the motor, you will almost always need to raise the converter to match.

T-5 Manual Transmission Conversion

5-Speed Shifter
Thanks to Ed for writing this article.

This article is a guide to installing a Borg-Warner T-5 manual transmission for the 5.0L V8 engine *. This conversion uses Mustang parts commonly found in the salvage yard, swap meets or auction websites.

* NOTE: Since the 5.0L V8 and 3.8L V6 share the same Ford small block bolt pattern, some of this information may be the same for V6 models as well; however, there are many more issues involved with installing a T-5 onto a 3.8L V6 engine in our cars. At this writing it is not recommended to use a T-5 on the V6 until much more research is made.

UPDATE: LMR has a great article and installation video for Mustangs that is almost dead on with the info below. They also have an extensive, in-depth parts list for this swap. Feel free to view it first so you’ll get a great idea. The video has a transcript in case you don’t wish to view it.





The most important part of the parts acquisition is to choose a transmission. For most people who plan to drive their car on the street, the obvious choice would be the 1987-93 Mustang V8 T-5 transmission. It’s cheap, plentiful, and has average durability. We bet you didn’t know that there are over 30 flavors of T-5 transmissions! They all have different maximum torque ratings, and gear ratios.

Of course, there are other options for transmissions. There are many aftermarket units available which have been improved or are designed to take the stress of “extreme” applications. You will have to seek these out, but they range from a T-56 (with six speeds), to a Tremec 3550 rated at 400+ foot lbs. of torque! There are also places that have assembled 5-speed conversion kits, complete with transmission and everything you need to do the job. Some parts are used though, so be sure to ask questions.

Whatever you do, don’t install a used clutch unless you have WAY TOO much time on your hands. A worn clutch that worked in another car may not work in yours, even with the same transmission! Ask around, usually the different brands and types of clutches have a very different pedal feel and ability to stand up to abuse!

The rest of the parts you will need: (items bulleted with a star instead of a circle, are optional)

  • Throw-out bearing: Usually your clutch comes with this. Make SURE!
  • Rear main seal (optional): Everyone says they have problems with these. We’ve never had one leak, but it is a BEAR to get at any other time. While replacing it is optional, it might be a good time to put this in while the tranny is out.
  • Pilot bearing: Order a 1987-93 Mustang V8 pilot bearing. We’re not aware of any differences in these.
  • Aluminum motor/bellhousing spacer/dust shield: This is the sheet of aluminum that sandwiches between the motor and bellhousing. If you don’t have this, debris can get into your bellhousing and rub up against your clutch—this is a bad thing!
  • Flywheel: You need a 1984-up V8 flywheel for any 1984-up 302 (5.0). As far as we know, they’re all the same since they have the 50-oz imbalance. If you can afford to go aftermarket aluminum, more power to you! If you have an older motor, you will need to have the flywheel rebalanced appropriately (such as the older 28-oz balance). Some people will tell you to resurface these, and others say that there isn’t enough meat on them to cut metal off. You can possibly “rough up” the surface with a sanding disk, without having it resurfaced.
  • Bellhousing and clutch fork: This will need to come from any 5.0 application, matching your transmission. (All the T-5, 302, bellhousings are the same, as far as we know). There’s a shield that goes on the side of this that covers the clutch fork after the install. Make sure you get the shield—it’s about US $30 new from Ford, and if you can get yours with the bellhousing, you save that much more money!
  • Clutch pedals: These can be had from any 1987-93 Mustang 4-cylinder or V8; some people have reported minor differences between the two, but in either case they both seem to work. You can also use the pedal assembly from any 1983-86 Turbo Coupe or XR7. Please note that since the 4-cylinder 1987-88 Thunderbird Turbo Coupe used hydraulic clutches, you cannot use those pedals with the 5.0 V8 conversion. Currently it is not known if you can make a hydraulic setup for that engine. Also, the 1994-up Mustang pedals may be able to be used but that also is unknown at this time. Decide at this point if you want a clutch-in safety switch. It should be on the pedal assembly, but if you buy from a yard they may have broken it, or removed it.
    5-Speed Pedals
    It is now possible to simply keep your factory automatic pedal assembly and add the third (clutch) pedal to it using Ford parts. See information below.
  • * Clutch quadrant: While you have the clutch pedals out, you might want to use a new quadrant. The stock pieces are plastic, and all of the people who sell the aluminum ones say the plastic ones break.
  • * Clutch cable and or adjusters: You can use the stock cable if you wish, but it just seems wise to put an adjuster in when you do this install. The stock cables do stretch over time, and you will eventually be happy that you did. If you use a firewall adjuster on your Cougar/Thunderbird, you will need to change your brake booster out for a smaller Mustang unit. The 1987-93 Mustang booster is the easiest bolt-in replacement. The 1994-up unit can be used, but requires redrilling one of the bolt holes in the firewall, and through the pedal assembly. Of course, the simple solution for this is to just buy an adjustable cable.
  • Exhaust hanger: The design of the manual transmission hanger and the automatic is different. In addition to using the manual transmission hanger, you may need to cut and bend anyy aftermarket X- or H-pipe hangers to fit properly.
  • Transmission Crossmember: If you examine your crossmember, you will see that it is either shaped like [—-] or like [____]. You can grind the welds on the ends, off, and then slide the horizontal piece up and down, in relation to the ends, or you can buy the manual transmission piece. Whatever floats your boat.
  • Bolts: Upper bell housing bolts (or washers to make up the extra length), since the top of the T-5 case is much thinner requiring shorter bolts. Pressure plate bolts, starter plate to bell housing bolts, transmission-to-bell housing bolts.
  • Driveshaft: Now would be a good time to go aluminum. You may have to go custom with this. If you have any info, send it along. If you like your stock heavy steel shaft, you can reuse it.
  • Radiator/transmission cooling line plugs: Remove your stock lines and cooler, and plug these holes.
  • Back-up light harness/neutral safety switch: This is Ford part # E7ZZ-15525-A if you’re buying new, or if you’re savvy enough, cut the AOD connector off and rewire to match the T-5 connector.
  • Dual exhaust conversion: If you haven’t done this, now would be a good time since you have to rip out most of the exhaust piping to do the conversion.
  • Trim/Console – For 1985-88 XR7’s, T-Bird Sport Coupes, and all cars with the optional console, all you need is the 1985-88 Turbo Coupe upper and lower shift boots, and the shifter bezel. This part couldn’t be easier if you already have a floor shift! You may have to trim the metal in the shifter area, to make room for the T-5. Owners of 1983-84 cars already have the factory console and would need only to find the cover plate, and cut the hole if necessary.
  • If you own a 1985-88 car with the factory consolette attached to the driver’s seat, then you could install a 1985-88 Cougar/T-Bird console. That also means either modifying or replacing the driver’s seat. (By the way, even though they are Fox cars it’s not recommended to try and make a Mustang or Mark VII console work in your Cougar/T-Bird. There’s just way too much work involved for just needing a console to house the T-5 shifter.)
  • Or you could cut the hole in the floor and cover it with an aftermarket boot, such as shown here (and honestly, this is one of the cleanest installs we’ve seen to date). It may limit the forward travel of the driver’s seat.
    5-Speed Shifter Install (Consolette)
  • Shifter – Now would be the time to install that shifter you always wanted with your T-5. They will improve the reliability of your transmission if you drive hard, or like to keep your arm on the shifter. They also improve shift feel, and will make it easier for you to beat it harder.

On a column shift car you will have to remove the column shift handle (simple pin removal) and all linkages. You should try to replace the steering column’s top cover with one from a donor floor shift car, to make it look nice. Additionally, there is a second shaft that runs alongside the main steering shaft, for the shift control arm. That’s what physically moves the linkage on a column shift car. It’s optional to fully remove that shaft but it does look nicer without it. It’s probably easiest to remove it from the engine bay side, instead of from the inside of the car. Unfortunately, if you have the optional automatic parking brake release (vacuum system), you might lose that since it’s attached to that shifter shaft. There may be a way to bolt that to the firewall though.




UPDATED: It is now possible to simply keep your factory automatic pedal assembly and add the third (clutch) pedal to it using Ford parts. Viewer William brought to our attention that his company, Silver Sport Transmissions, makes a conversion kit for all Fox vehicles converting to a 5-speed setup. Click here to view the kit and get up-to-date pricing information. If you fear swapping out the pedals or don’t want to hunt down 5-speed pedals, this might just be a very simple and economic solution for you.

This is probably the most time-consuming part of the job. Expect to spend a full day on this part alone, your first time out. To make this as easy as possible, you will want to remove the driver’s seat and the entire steering column. Removal of the steering column sounds like a chore, but it’s not really that bad. Before you do anything else, get your trouble light out, and DISCONNECT THE BATTERY. This will prevent blown fuses, fires, and electrocution!

Next, remove the steering column covers, and all panels surrounding it. Unhook all of the harnesses you can get to on the steering column, including the multifunction turn signal/wiper switch, ignition switch, key chime wire, and so on. There are 4 main nuts that hold the column in, underneath the dash. Take those out, and the column should drop freely from the dash. There is one bolt in the engine compartment, accessible from underneath, where the steering shaft bolts together (it’s within about 4 inches of the firewall). Remove that bolt, and you should be able to take the whole column out of the car from the inside. Set the column outside the car so it’s not in your way.

At this point you should be able to lay under the dash fairly easily, and see everything that’s in your way. The worst part is managing to get those diagonal dash braces out of the way. Some people end up bending them out of the way, but you may want to remove them.

The 4 nuts on the firewall that hold the pedals in are fairly easy to remove with power tools, but they take a lot more time to reinstall. The upper right nut takes quite a long time to reinstall. Tear everything out of there that you need to, and once you get the pedals loose, you’ll have to maneuver and rotate them around for awhile before you get them totally free.

Reverse this procedure for install of the new pedals. If you’re doing this whole job all at once, you will want to hook up the clutch cable with the column out, after you get the transmission in. If you’re not, make sure you leave the under-dash covers out so that you can get in there to hook up the cable. Note: if you’ve read articles on the Mustang T-5 conversion, you should know that you do not have to worry about rerouting a speedo cable, unless you have an 1983-84 Cougar/T-Bird which still uses a cable.



Get the car all the way up on some jacks tands or wheel ramps or both. As high as you can get it (but not higher than you can reach).

Remove the H-Pipe (or Y, for you deprived folks). Remove the muffler and tailpipe IF NECESSARY.

MARK YOUR DRIVESHAFT AT THE REAR. Put a line on the shaft, and on the pinion, BEFORE YOU TAKE IT OUT. Your driveshaft is supposed to be “balanced”, but it can make a major difference to your ride quality if you don’t do this. Then remove the driveshaft.

Remove the AOD transmission, AOD flexplate, tranny cooler lines, shifter, shift cables, and TV/kickdown cable (you can sell it all on eBay!). Plug the holes from the cooler lines in the radiator.

Install your rear main seal, if desired. Shoot some WD-40 into the end of the crank, making sure the hole is clean, for the installation of the pilot bearing. Install the pilot bearing using a socket that’s slightly smaller than the pilot bearing, and knock it in (don’t break it though!). Install the new flywheel, using blue thread locker on the attaching bolts. Install the clutch disk and pressure plate. Install the throwout bearing and then the bellhousing. Make sure that the fork is installed correctly—it should poke straight out of the side of the bellhousing, pointed slightly towards the rear of the vehicle. Make sure that the fork is correctly interfacing with the throwout bearing and the bearing is flat against the pressure plate. It will be very tight, and you will be able to move it very little with your hands (maybe 1/2″, with moderate effort).

Now install the T-5 transmission. Make sure that everything is lined up inside, with the shifter and all, before you proceed! It seems to be easier to install without the shifter handle. Install the crossmember and exhaust hanger. Wire up the reverse light/neutral safety harness. Hookup the clutch cable. It should be installed on the FARTHEST “tang” on the quadrant. The shift fork will be about an inch from the back of the bellhousing when everything is installed correctly. Reinstall the driveshaft and exhaust.

Install your shifter handle and “test drive” it, on the jack stands. (MAKE SURE THE VEHICLE IS STABLE) When the clutch is pressed in, and the vehicle is running and in first gear, the wheels shouldn’t spin at all. The wheels should begin to turn when you’ve released an inch or two. If that test goes okay, you can drop it, and take it around the block. If your clutch is new, keep the burnouts to a minimum for the first 50 miles or so. Listen closely for slippage. When the car is in gear, the motor should not “spin” up, without a correlation in acceleration. If you have slippage, the clutch cable could be adjusted improperly, or you could have a bad clutch. If not, finish bolting in your interior trim, and most of all…


Column-to-Floor Shifter Conversion - AOD


AOD Floor Shifter

If your AOD-equipped Cougar has the column shifter, you know how un-sporty that makes the car feel. While it gets the job done, there’s nothing like having a floor shifter (particularly in conjunction with a console). Just because your car never came with a floor shifter doesn’t mean you can’t have one—this article will step you through installation of an AOD floor shifter in your car.

Before you go rooting through the local salvage yard for parts, you must know the semantics behind doing such a conversion. The shifter and transmission must be in sync with each other or you’re literally not going anywhere. With a column shifter, your AOD is NOT ready for a floor shifter, so there is labor involved in that. Then you must work up the guts to cut a hole in the perfectly good floorpan. And you must also install a console in your car if you don’t already have one. This is a very involved project that is not for the weak. But if you’re convinced you can do it (or are paying a mechanic to do it for you), read on. It is highly recommended that you consult with a professional, refer to a shop manual, or both before you proceed.


Setting Up Your Transmission

You will have to do two things to the AOD transmission to prepare for a floor shifter: flip over the shifter lever, and get the correct arm for the outside of that lever.

First the shifter lever itself—it’s what does all the action in the transmission, as it physically determines the gears. A small part of it is on the outside of the casing, but the business end is on the inside. With your current shifter setup, you’ll notice that the linkage (or cable, depending on the car) is coming from the front of the car. With the floor shifter the cable (or linkage) will come from the rear side of the car. Without that lever in the correct configuration, P will be 1 and 1 will be P on the shift indicator (in other words, things will work totally backwards). The old trick is to remove the shifter lever from the transmission, simply flip it over, and reinstall. That will do the job just fine, but if you want to get the actual correct Ford part you can do so—either way is cool. This is a complex job and not to be taken lightly, as it involves removal of the valve body. It’s also why you have to do everything in one shot.

The shifter arm is on the end of the shifter lever that’s sticking out of the casing. On your car the arm (where the linkage or cable is currently attached) is facing toward the front of the car. For the floor shifter the tab must be facing down. You can simply order a new arm from the dealer for a few dollars.


AOD Floor Shifter Diagram

You will need to also find a shifter cable bracket that attaches to the casing. This bracket will hold the cable in its correct position, away from moving parts and from the heat of the transmission. The bracket can also be ordered new, and you must get the bracket for your transmission type. The holes to attach the bracket to the casing are already there so you need not worry about tapping new holes. Refer to the illustration for the bracket location (upper righthand area of the image).


Transmission Replacement (Optional)

Perhaps the information above scares you a little…or maybe you feel your transmission isn’t up to par anymore. Or maybe you’re looking for an excuse to upgrade to a more solid transmission. In any case, it is perfectly alright if you simply use another transmission that’s already set up for a floor shifter. You’ll probably be looking at an AOD, which is a logical choice. However, you have to know the difference in AOD’s before you shell out your hard-earned cash. The following chart will help you determine what AOD from a factory floor shifter car will work in your car:

Model Years
Direct Fit for AOD?
Fox Cougar / Thunderbird with floor shifter option
Mustang V8
Crown Victoria / Grand Marquis
Lincoln Mark VII
Yes, with modification to driveshaft length
Lincoln Continental (RWD), Town Car
Yes, with modification to driveshaft length
MN12 Cougar/Thunderbird (including SC and XR7)

Technically the insides of all the Fox AOD’s are the same, save for the Mustang V8 version which seems to have more clutch packs from the factory. The MN12 non-supercharged V6 AOD’s are identical to Fox AOD’s. The supercharged AOD, however, has had significant enhancements including a one-piece input shaft, upgraded C-servo, and a revised valve body. If you’re looking to just swap an AOD in, the SC-spec AOD is the one to get (if you can find one), or the Mustang AOD. You can use the Lincoln AOD (Mark VII, Town Car or RWD Continental) but it is heavier and has a longer tailshaft, which means you must have your driveshaft shortened and that’s an additional expense you should avoid if possible.


Determining Your Shifter Type

Not all factory Cougar/T-Bird floor shifters are alike! You must make sure that you have the shifter that’s correct for your transmission type. All C3, C5 and AOD transmissions will use the same kind: with 6 detentes, or notches. You cannot use a shifter meant for an A4LD transmission, like those used in 1987-88 Turbo Coupes, since they have 7 detentes. The following chart will help you determine what’s needed to use on your car, and subsequently from what car that you can use the shifter:

Your Transmission
No. of Detentes
Floor Shifter Reads:
C3 (4-cylinder turbo, 1983-86)
P R N D 2 1
AOD (V6 or V8, 1987-88)
P R N (D) D 1
A4LD (4-cylinder turbo, 1987-88)
P R N (D) 3 2 1

The only difference between the C3 and AOD shifters is the indicator plate that’s bolted to the shifter. So if you have an AOD but can only find a C3/C5 indicator plate, for example, you can use it but you’ll just have to remember that D is actually overdrive, or (D). Vice versa is also true— (D) would just be D on a C3/C5.


Parts Acquisition

Like most things for your car, you’re going to find the local salvage yard or eBay to be the most accessible places to find the parts for the floor shifter conversion. You will need the following:

Shifter Assembly with Cable


AOD Floor Shifter Diagram

You will need to get the entire assembly with the cable attached and all bolts as well. It is very difficult to change a cable, or attach one to the shifter if it’s not there. The factory Cougar/Thunderbird AOD shift cable is extremely difficult to find these days; using a Mustang cable may be possible but that is yet to be determined. Refer to the drawing for all the specifics and parts necessary.


Shifter Cable Bracket

If you can get the cable bracket from the donor car for the side of the transmission, that’s perfect. It may sound strange but mid-1980’s Crown Victorias and Grand Marquis with the AOD also had that bracket, so there you go—one more place to find it. It’s relatively inexpensive new if you want to use a new part instead, your choice. Again refer to the diagram above for more information.


Steering Column Top Cover

When you remove the shifter arm from the column, you’ll have a hole in the top column cover where the arm was. Simply replacing the top cover with one from a floor shift car will make things look complete.


Console/Shifter Cover Plate

If you already have a console, you’ll simply need to get the shifter cover plate to complete the console trim. But if you don’t have a console, you’ll need to get the whole deal from a donor car. This includes all metal brackets (3 in all), screws and wiring. It’s pretty much futile to put in a factory floor shifter and not have the console.


Radio Panel for Console Cars (1985-88)


Cougar Console Diagram

If you are installing a console at this time, you’ll need the console-oriented radio panel to complete the transition between the dash and the console. You’ll also need to lose the push-out ashtray and put a lighter panel in its place. Those can all be had from the donor car. Refer to the illustration.



Before you begin, if you don’t have the console already, you will need to install it first. This is because you will use the console as a guide for cutting the hole in the floorpan. It is extremely difficult to cut that hole without the console in place. Make sure the console is exactly how it needs to be before starting the floor shifter conversion!

First and most important, disconnect the vehicle’s battery! Then remove the console cover plate and set it aside. Take a thick black magic marker (or white china marker, for those with darker-colored carpeting) and trace the edges of the console on the inside in that area. This will represent the maximum limits of the console, and consequently the farthest you can cut when you begin to do so. You can then remove the entire console assembly from the vehicle and set it aside.

Get the car all the way up on jack stands or wheel ramps, or both. You’ll want the car as high as you can get it but not higher than you can reach. You do not have to remove the H-pipe or Y-pipe unless you are removing the whole transmission. MARK YOUR DRIVESHAFT AT THE REAR. Put a line on the shaft, and on the pinion, BEFORE YOU TAKE IT OUT. Your driveshaft is supposed to be “balanced”, but it can make a major difference to your ride quality if you don’t do this. Then remove the driveshaft. Note that if you must have your driveshaft shortened (when you use a Lincoln AOD), you must either take measurements before removing it. Talk to your driveline specialty shop first.


AOD Column Shift Removal

Next, remove all shifter linkage from the vehicle, including the brackets by the exhaust manifold on the driver’s side. When you’re done with this step, get back inside the car and get ready to remove the shifter lever from the column. Remove the steering column covers (top and bottom) and examine the lever itself. Note that it is held onto a separate shaft, known as the shifter shaft (highlighted in orange in the illustration at right). This shaft runs through the firewall to the engine bay, where the linkage hooks onto it. Turn the key forward and put the car in N, then turn the key back. Tap the pin from the shifter arm and remove the arm. Note that the lever MUST be in neutral if you’re leaving the shaft in the car.


AOD Shift Linkage Diagram

You must decide at this point whether or not you’re going to remove the shifter shaft from the car. It’s not necessary but it does make for a clean looking installation, and it also eliminates some weight and unnecessary components from the car. If you’re going to eliminate it, you’ll need to remove all the brackets from down by the pedals and from the engine bay (see illustration). Note that if you have the automatic parking brake release option on your car, the vacuum assembly is attached to the shifter shaft. You may need to remove that section and attach it to the firewall in order to keep its functionality; otherwise you’ll lose it.


AOD Column Shift Removal

The shaft itself is pressed into the actual steering column casing by the steering wheel, on the right side. You may have to remove the steering wheel to see it. Once you’ve detached all the brackets by the firewall, get a punch and hammer and place the punch on the end of the shifter shaft, or follow the directions in the diagram. Then go to town—it’s going to take a little while to get the shaft to pop out of the casing. But once it does, the entire shaft should be free to remove. You may find that it’s easier to remove it from underneath the car, rather from inside. Take your time and be patient. Once you’re done, you can replace the steering column covers.

  • If you are doing the internal transmission work yourself, proceed to remove the shift lever, flip it over, and replace it. You can reassemble the transmission at this point. Also, install the new arm on the outside of the shift lever.
  • If you are removing the transmission, do so now. Once the transmission shop has finished with flipping the arm for you, change the arm on the outside of the shift lever. Don’t put the transmission back in just yet though; it’s easier to install the floor shifter with the transmission out of the car.


AOD Floor Shifter Hole

The next step involves cutting the hole for the floor shifter. Cut the carpeting near the lines you drew, but come in about 1″ from the actual lines. If you cut too much out, the console may not be able to cover it up. Remove the insulation as well, until you can see the actual floorpan. Be extremely careful not to cut any wiring! You now need the template to draw on the floorpan which you can download below. Note that it is roughly “plus”-shaped. Follow the directions and carefully measure out the areas until you’re confident you have the spot. You can be off a little but it’s imperative to get the cut as close to perfect as possible. Draw the outline in the area. Then….get out the reciprocating saw and make your cuts. Be very careful as the metal is not real thick and can jump around. Refer to the photo at right for a reference to what your shifter hole should look like when cut. For the bolt holes you need only to drill them out and slot them. Install the clips to the mounting holes, then bolt the shifter in temporarily. Be sure to put the shifter in Park.

For a template and instruction manual on cutting the shifter hole in the floor, download the PDF file here.

A technical note here: cars with factory floor shifters have a reinforcing plate welded to the floorpan underneath the actual shifter. This, in turn, raises the shifter up about 3/4″. The instructions provided here do not allow for this reinforcing plate. If you have the time and the technical know-how to fabricate one, feel free to do so. Or if you’ve managed to acquire the plate from a donor car, install it now. Otherwise, the rest of this article will assume that you’re simply going to bolt the shifter directly to the floorpan. While this is perfectly fine, any additional reinforcement you provide can be beneficial.

AOD Floor Shifter Diagram

Now you can reinstall the transmission, if it’s not already in the car. Reinstall the driveshaft and be sure the transmission itself is in Park. Then install the bracket on the side, the cable to the shifter arm, and the kickdown cable (again refer to the illustration at right). You’ll note that there is an adjustment where the shifter lever bolts to the arm; you’ll be adjusting it later but for now, clamp the nut down in the middle of the slot. You will now have to install a clamp to hold the shifter cable away from the exhaust, and from hanging down underneath the car. From the factory the clamp is pop-riveted to the floorpan, underneath the driver’s seat. Be VERY careful when drilling the hole so that you don’t pierce any wiring. You can use a pop rivet or a simple screw to attach the clamp. Get everything buttoned up underneath the car and you’re almost home free. But be sure to leave the car in the air for the time being.

Next, put the console back in the car along with the radio panel. Put it together all the way, and temporarily install the new shifter cover plate. You’re going to concentrate now on getting the shifter to look good, and line up with the cover plate. There is actually a bit of latitude in adjustment here. You can move the shifter, or the indicator plate, or the bezel on the cover plate, to get everything nice and square. If you don’t have any reinforcements underneath the shifter, you will notice that the indicator plate is sunk below the cover plate. You will need to use shims on the indicator plate (washers are fine) to bring up the plate. Factory floor shift cars have their indicator plate sticking up out of the cover plate about 1″. It would probably be impractical to try and raise it that high. Once you’ve got it all looking good, you’re pretty much done. The last step is to check the gears, and having a friend help here would be a good thing.

Both the shifter and transmission should be in Park. Push the shifter button in, and go through all the gears. Your indicator should be in the middle of each letter as you do this. You should feel no binding or resistance when shifting. If either the indicator is off, or you do feel resistance, the cable must be adjusted at the shifter arm on the side of the transmission. Loosen the nut, slide the cable, and carefully tighten the nut, then cycle through the gears again. Once you’ve got it perfect, put the car in Park, jack up the car, take out the jack stands, and lower the car. You’re now ready to start the car and put it in gear. If all goes well, you’ve done the job correctly and are finished. Enjoy!

Column-to-Floor Shifter Conversion - C5


Thanks to Trevor (aka RavageWolf) for writing this article.

We estimate that probably 70 percent or more of all 1983-88 Cougars and Thunderbirds had a column shifter as standard equipment. The floor shifter was reserved for XR7’s, Turbo Coupes, and those souls willing to pay the extra money for the console and floor shifter package if they were even offered that model year. Yet it’s almost universally the one thing that most people want in their cars, and with good reason. It’s convenient, allows things like the analog instrument cluster, lets you manually shift gears easier, and…well, it’s just sportier. Of course, just because your car never came with a floor shifter doesn’t mean you can’t have one.

Before you go rooting through the local salvage yard for parts, you must know the mechanics behind doing such a conversion. The shifter and transmission must be in sync with each other or you’re not going anywhere. With a column shifter, your trans is NOT ready for a floor shifter, so there is labor involved in that. Then you must work up the guts to cut a hole in the perfectly good floorpan. And you must also install a console in your car, if you don’t already have one. This is a very involved project that is not for the weak. But if you’re convinced you can do it (or are paying a mechanic to do it for you), read on. It is highly recommended that you consult with a professional, refer to a shop manual, or both before you proceed.

NOTE: This step-through is only for setting up the C5 to accept floor shifters.


There are two ways to do your column-to-floor shift conversion:

  • Option 1: Use the factory 5.0L V8 floor shifter for the AOD (1987-88 Cougar/Thunderbird). Since this shifter was designed for the AOD trans, it won’t make a direct fit onto your C5 trans but it does fit the console perfectly.
  • Option 2: Use the Fox Mustang cable-operated floor shifter (V6 Mustangs/Capris). This will fit perfectly with your C5, since this Mustang floor shifter is for the C5. The only drawback is that it won’t look too good in your center console unless you make modifications.

Mustang V6 Shifter



NOTE: All parts needed will come off Fox Mustang/Capri’s with cable shift (most V6 models) and 1987-88 Cougar/T-Bird with the 5.0L V8.


  • 1 – 1987-88 Cougar/T-bird 5.0L floor shifter, or Fox Mustang cable operated floor shifter (found on V6 Mustangs/Capris with the C5 trans)
  • 1 – Console cover plate
  • 1 – Complete Mustang/C5 cable bracket *
  • 1 – Shift lever (points down) from C5 transmission from a Mustang/Capri
  • 1 – Kickdown bar (piece of metal connected from the carbeurator to the transmission) off the Fox Mustang with cable shift
    1 – New transmission pan gasket and filter.

* If using the Cougar floor shifter, you must modify the lower portion of this bracket to fit the cable, meaning you must hack off the existing cable going through.


  • 22mm metric open end wrench
  • Pliers
  • Wrenches
  • Sockets
  • Torque wrench




For the 5.0L floor shifter (if using the Mustang shifter, skip this)

Because this shifter is meant for the AOD, it will not work without modifications to make it compatible with the C5. Please read through if you want to keep that factory look by using this shifter.

  • Since the AOD shift bracket won’t work, you need to modify our own. Taking the shift bracket off the Mustang w/C5, remove the cable running through the bracket. Next, cut off the side metal, until it’s level with the bracket.
  • The hole you see before you (refer to Figure 1) is too small for the floor shift to fit. You must enlarge the hole by using a drill bit, and shaving the edges of the hole until it’s big enough.
  • Cut a horizontal slot to allow the cable to slide in.
  • Drill a corresponding hole to the shift cable and bolt the cable on.

The result: a custom made bracket! But when you try to install the bracket, you’ll notice the shift cable is about 1 1/2″ short of the shift lever. The problem can be solved by doubling over a sheet of metal, and drilling corresponding holes to match the shift lever and shift cable end.



Note: This should be done by a professional; in other words, sending your transmission to a trans shop to flip the shift lever for you (unless you’ve got the guts to get down and dirty with transmission fluid!)

  • Set up your car safely on jack stands, or on a lift (if you’re so lucky).
  • Remove the kickdown bar and column shift connection from the transmission, and remove the sensor. Place spare parts in safe area.
  • Proceed to remove the transmission pan bolts. Be prepared for transmission fluid to come out.
  • Once fluid starts to come out, quickly place a large bucket (able to hold more than 5L of fluid) underneath.
  • Remove the transmission pan and old filter.
  • Carefully remove the valve body, and store bolts in safe place.
  • Find the nut that holds the shift lever, and remove the nut using the 22mm wrench (refer to Figure 2).
  • Carefully remove the old shift lever. Note: you will have problems removing it since there is not much space to work with. If you become complete frustrated, hammer out the floor pan adjacent to the lever.
  • Install the new/used shift lever off the Mustang, There should be no clearance problems when installing.
  • Line up the shift gear with the lever and put the nut back on. Reinstall the valve body. Pay close attention that the shift gear lines up with the piston like thing.
  • Test shift the new lever, making sure it can go P R N D 2 1. If you’re missing some gears, realign the piston thing with the shift gear.
  • Install the new filter and gasket, and bolt the pan back on. Torque to 11-16 ft/lbs.
  • Reinstall the sensor, and install the kickdown bar off the Mustang (you need this bar because the stock one with the column shift will interfere with the shift lever).
  • Test the kickdown bar to make sure that it is able to move freely (if you push up too hard it will get stuck, and you will need to remove the valve body to get it unstuck!).
  • Install the Mustang cable shift bracket.
  • Hook up the shifter cable to shift lever.
  • Calibrate the shifter.
  • Add about 4L of new transmission fluid. Start you engine and let it run for about 10 minutes, then check transmission fluid level. Add more if needed.
  • Enjoy your floor shifter!

For a template and instruction manual on cutting the shifter hole in the floor, download the PDF file here.

Turbo Coupe 4-Lug Disc Brake Rear Axle Swap


More than likely you’ve got the 7.5″, open-gear rear axle with the 2.73 gear in your car. While decent for fuel economy it’s rather lukewarm for performance. If you don’t have the Traction-Lok option, you’re missing out on greatly increased traction on slick surfaces. And we all know how marginally adequate that drum brakes are. If you’re pining to upgrade and want to keep 4-lug wheels, we’ve got the swap for you.


Thunderbird Turbo Coupe Rear Axle

A rear axle swap is an efficient way to get what you want. Now if you can find a 1988 Cougar/Thunderbird 8.8″ rear axle with drum brakes and Traction-Lok, then that’s one alternative. Problem is, they’re extremely difficult to find, and only come with the 3.08 gear from the factory, at best. And the Mustang 8.8″ is not as wide from the factory as one made for our cars, so that would necessitate new rims with a greater offset or tricky axle shaft/brake swaps. But, if you want a factory-width 8.8″ axle with a great 3.55 or 3.73 gear, Traction-Lok, axle dampers and disc brakes to boot, then you need look no further than to our sister car, the 1987-88 Thunderbird Turbo Coupe.

Because the Turbo Coupe was powered by a 2.3L 4-cylinder engine it required a really tall gear to get the car moving. Therefore, you’re going to get an excellent gear from the factory. The automatic Turbo Coupes have the 3.73 gear; manual cars came with the 3.55’s. There is hardly a difference between the two gears, from a seat-of-the-pants perspective, but the difference is there. The downside to the whole conversion, besides a little plumbing, is that you have the potential to lose approximately 1-2 mpg with the taller gears (although several people have reported an actual increase in fuel economy). And, the 8.8″ rear axle is a bit heavier than the old 7.5″. This should not deter you, however, from aspiring for this conversion. The benefits far outweigh everything else. This is fast becoming one of the most popular swaps for our Cougars due to its relative ease of installation and plentiful sources.

There is a Troubleshooting section at the end, so if you run into any problems during or after installation, or you just want to check things before you install, the information is here for you.


Parts Needed

You will need the following items from an ’87-’88 Thunderbird Turbo Coupe:

  • Rear Axle Assembly
  • Emergency Brake Cable Brackets
  • Quad Shocks and Brackets (optional)

You will need the following new items:

  • Brake Master Cylinder
  • Proportioning Valve * (see below)
  • Proportioning Valve Plug * (see below)
  • 4 feet of 3/16″ Brake Line
  • 14″ of 1/4″ Brake Line
  • New Rear Brake Caliper Hoses (check old ones first)
  • New Emergency Brake Cables (check old ones first)


Rear Axle Assembly

This is the axle and all related components (rotors, calipers, etc.). Most of the time the rear rotors can simply be sanded down and reused, so you may not have to buy new ones. The calipers can freeze up, so you may want to have them checked just in case. (See the Troubleshooting section below for more info on these). The axle tag, located on the differential (aka “pumpkin”) cover, will help determine the axle ratio—3.55 or 3.73—with a number and letter code. On the bottom row of the tag, you will see a code like ‘3Lxx’, where the ‘xx’ represents the last two digits of the axle ratio and the ‘L’ indicates a locking center.


Emergency Brake Cable Brackets


Emergency Brake Lever

Since the Turbo Coupe has disc brakes, all the emergency brake cables will be different from your stock ones and will also need to be moved slightly. You will need all the related brackets for the cables as well as the intermediate spring assembly. Once you’re under the car it’s self-explanatory. These are proving to be some of the toughest parts to find for this conversion, so be alert.

The main bracket is called the equalizer bracket and may have been used on later mid-90s Ford Taurus vehicles as well. It is the main junction between the cable coming from the pedal, and the two cables going to each side of the axle. We believe the original part number has been superseded with this one: F6DZ-2K390-A. It is getting extremely difficult to find them, new or used. However, it should be possible to either adapt a Mustang equalizer bracket, or an aftermarket one, for use with this swap.

Another bracket holds the cables up near the floorpan under the driver’s seat. It bolts where a peg currently is to hold the non-disc brake ratcheting assembly. Again, we will try to find a part number. A simple bracket could be created from metal to replicate the function, and the peg has a small hole to accept a clip or cotter pin. That’s all that is really needed here.


New Emergency Brake Cables

Emergency brake cables will be needed to adjust the calipers periodically. The TC rear axle uses three cables: one that attaches to the pedal, and both driver and passenger side cables. These cables have been discontinued by Ford but aftermarket cables are available at good auto parts retailers. Before installation, it’s recommended that you further lubricate the cables which will help prevent any freezing.

Raybestos lists these part numbers:

  • Driver’s Side – BC93634
  • Passenger’s Side – BC93638
  • Pedal to Junction – BC93658
Axle Damper (Quad) Shocks and Brackets (optional)


Quad Shock Bracket

If you want to further increase handling and help control the twisting action of the rear axle, you can also get the Turbo Coupe axle damper (a.k.a. “quad”) shock setup for your Cougar. These shocks are horizontal, not vertical like your main shocks, so they can greatly help to tame the axle’s behavior. The Turbo Coupes all used them and the bracket is there on the rear axle for them. All Cougars and Thunderbirds from mid-1983 through 1988 have threaded holes in the rear frame rails for accepting the axle damper shock mounting brackets, so all you need is to bolt that bracket in and you’re all set up. The cool thing about quads is that they don’t behave like normal shocks; once you push or pull it in a direction, it stays there and does not retract under gas-charged pressure. Therefore they’re easy to put in. They also last a good long time, at least twice as long as standard rear shocks. The stock axle dampers from the Turbo Coupe just may be fine to reuse. If not, they’re usually inexpensive at parts stores; you may need to order them for a Mustang GT as an “axle dampener”. It’s also important that you try to get the stock bolts for the quad shocks. They’re all discontinued and they’re also metric.


Brake Master Cylinder

Rear discs can require additional brake fluid capacity, therefore may you need to replace the master cylinder. For 1983-86 cars, you will need to replace your stock one with a 1984-86 Crown Victoria master cylinder (1-1/8″ bore). For ’87-’88 cars with the aluminum body/plastic reservoir, you can more than likely reuse yours with no modifications. Several people have reported that it works just fine, with no low pedal feel or difference in braking whatsoever. Check the Troubleshooting section below for more info on this.


Proportioning Valve

Your stock proportioning valve is pre-metered for drum brakes (around 70% of the brake fluid to the front, 30% to the rear). Rear disc brakes, with their increased fluid volume, can handle more of the braking duties. This means you need to decide what to do with the brake proportioning. There are two schools of thought: gut yours and install an adjustable prop valve, or replace yours with a prop valve from a factory rear-disc Ford automobile.


Proportioning Valve

Now several people have reported that they used a stock 1987-88 Turbo Coupe factory disc brake proportioning valve with no problems. Same with a (Fox) Lincoln RWD Continental. We’ve even heard from a person that used an old 1978 Lincoln Versailles prop valve. So long as the Ford car had factory rear discs you should be able to use it. Remember that you will be stuck with the factory brake bias; there is no adjusting that valve. But for most people that probably won’t be much of an issue. Best of all, it should be a simple remove-and-replace deal.


Adjustable Proportioning Valve

The adjustable proportioning valve will give you a little more control over the front/rear bias. Essentially you will gut your stock prop valve of its spring and plunger, and install a fixed plug on the end (see below). Your stock prop valve then becomes a simple brake line junction where all the lines meet. The adjustable prop valve goes in-line, between the rear port on the master cylinder and the stock prop valve, and the rear brake line goes into the new prop valve. A good inexpensive unit can be purchased from Summit Racing or similar company. You will need some adapters and some short brake lines in order to fit this valve up to the master cylinder. We do not recommend using brass adapters, as they have the potential to leak; use steel ones if possible.

Fixed Proportioning Valve Plug

Proportioning Valve (Gutted)

Proportioning Valve

Currently available as a Ford Racing part (p/n M-2450-A) as well as being available at Mustang performance websites, this fixed plug will reside on the end of your old proportioning valve. After the new master cylinder and prop valve are installed, and before you put in any fluid, you must essentially gut the stock prop valve. The end facing the front of the car must be removed and the spring and plunger inside must be taken out. The new plug will go on, and that’s it. Be sure to save the old parts.


New 3/16″ and 1/4″ Brake Lines

1983-86 Cougars have the stock 3/16″ brake lines from the master cylinder to the back, along the passenger side framerail. On 1987-88 non-turbo cars the lines can be on the passenger side also; the Turbo Coupe the brake lines ran down the driver’s side and were 1/4″ to handle the higher volume of fluid. However, it is very expensive and impractical to replace all your car’s brake lines. Therefore, new lines on the rear axle itself will need to be installed. One side will use the 4′ section of 3/16″ line (driver’s side on ’83-86), and the other side will use the 14″; piece of 1/4″ line. You will also need a 3/16″-to-1/4″ adapter for the longer side, where the line enters the junction for the caliper hose. This is because you will use your stock brake junction; one side is 3/16″, the other side is 1/4″. We do not recommend using brass adapters, as they can leak fluid; steel adapters work better. You can purchase a line bending tool for about $7 or so; that’ll help you get the funky bends you need to jump the center section of the axle. If this all sounds sort of strange, don’t worry—it’ll become clear to you as you attempt to hook up the brake lines.


New Rear Brake Caliper Hoses


Rear Brake Hose

While the rear end will come with brake caliper hoses already attached, chances are they may not be working to full capacity. Brake hoses will naturally decay from the inside out, meaning you won’t spot the problem until the erosion is complete. The easiest time to replace them is beforehand; you don’t need to do this but it’s definitely worth considering. Price is around $30 US each. You will need a T45 Torx tool to remove the stock bolt that holds the brake hose bracket onto the axle housing.




Banjo Bolt

You’ll also need new brake line (a.k.a. “banjo”) bolts to hold the brake hose onto the rear caliper. Each one comes in a kit with two brass washers (you need one bolt and two washers per side). Always use new brass washers when removing and replacing the brake line from the caliper. These bolts are available at auto parts stores as well as the Ford dealership. One washer goes under the brake caliper end, the other on top, then the bolt goes through all. Be sure to tighten the bolts really hard in order to crush the washers, creating a leak-proof seal.

The Thunderbird Turbo Coupe rear rotors are unique to that axle. You cannot use rear rotors from any other Ford car. The original rotors are made of organic compounds and cannot be easily turned (machined) like a front rotor, at least not without a special organic cutter. All that is usually necessary to clean up an original-style rear rotor is to use 150-grit sandpaper or to use a wire wheel to remove the rust. If the damage to a rear rotor is found to be significant, an all-new rotor must be purchased. New rear rotors are reported to be non-organic, meaning the should be able to be turned in a normal fashion.


Ford Rear Disc Brake Piston Tool

When replacing rear pads with new ones, don’t forget to have the piston turned in on the calipers. The notches must be in the 12 o’clock and 6 o’clock positions in order for the pads to fit properly. If you don’t want to take the caliper off and have the piston pushed in by someone else, there is a special Ford rear disc brake piston tool that you can use with the caliper still on the axle. It’s available at good parts stores. By the way, if you ever do remove the caliper and you’re not changing the pads at all, you should simply need to reinstall them. There should be no need to have the pistons turned in.

You’ll need new C-clips to hold the emergency brake cable in the caliper housing. They’re available in a 20-pack at your Ford dealer, p/n 97413-S.

You will need to use your emergency brakes more often now, if you don’t already. The cables help adjust the rear calipers; they need to be adjusted every few weeks or so. Also, this will keep the cables from freezing up due to not being used. If you haven’t noticed already, e-brake cable freezing is a common problem with Cougars so if you’re spending the money on this rear axle, you need to get in the habit of showing a little love to the e-brakes.

As with all lower (numerically higher) gear changes, you’ll need to replace your transmission’s driven gear with the correct gear. You have to do this in order for your speedometer to be fairly accurate. Now this has been a source of confusion from time to time, but in reality it’s not too difficult to figure out. There are several online calculators where you can input your tire dimensions and drive gear (usually 7 or 8 teeth), and get the approximate number of teeth needed for your driven gear. Most people end up needing a 23-tooth gear. In years past this was a problem because the only 23-tooth gear available was for manual transmissions. While it worked, it also got shredded rather quickly and needed replacing every 5,000-10,000 miles or so. Fortunately companies are now offering specific automatic (AOD) transmission 23-tooth driven gears that should last a lot longer.

The speedometer driven gear is attached to the end of the vehicle speed sensor (VSS) that is bolted to the side of the transmission. One 11mm bolt holds in the assembly, then remove from the transmission housing. You’ll see the colored driven gear on the end. One C-clip holds it in place.



This is a rather large job; a good weekend may be enough to get it done. The upper and lower control arms can be reused, as well as the sway bar, if so equipped. Always get NEW brake pads for the back; don’t try to reuse old ones. Remember to use only DOT 3 or higher brake fluid; synthetic fluid is very affordable and should be seriously considered. You should need 2 quarts of fluid total. Bleed all 4 brakes—don’t forge that air is now introduced to the lines. Make sure you bench bleed the new master cylinder to prime it up for use. You may need to bleed the brakes several times in order to increase pedal feel.

Before you install the new axle, remove the pumpkin cover and check the axle fluid to make sure it’s fine. This is the absolute easiest time to change fluid if you need to. Again, we recommend synthetic fluid, with limited slip additive (available at your local Ford dealer). Check the old fluid for any metal shavings—if you find some, the ring and pinion gear may be bad. Get this inspected immediately! After installation, take it easy on the axle for the first few hundred miles just to get the fluid broken in. (Read: please don’t take the car to the drag strip right away.) If you hear increased noise from the back while driving it could just be the noise associated with a lower (numerically higher) gear. You may also hear the rear brake rotors working when you hit the brakes; this is normal as well. If you hear a humming or whistling sound back there, though, get it checked ASAP!!!

When setting the front/rear brake bias, remember that you want the back brakes to lock up just after the front brakes, NEVER the other way around. This may take a few tries to get right. Try to get a nice open parking lot to do all your adjusting.



So maybe the rear end is installed and you’ve set everything up, except you’re not stopping that well. Or maybe you have the brakes all the way to the floor and one of your rear wheels is still spinning. You’ve definitely got a problem somewhere, and this section should help you troubleshoot to find that problem.



One of the most common problems concerning rear disc brakes is that the calipers will “freeze”. This isn’t quite accurate; either or both of the 2 slider pins have rusted shut into the lower caliper housing. This allows the rear wheel to spin freely at idle in drive gear with the brakes on—not very safe on an icy parking lot. The culprit will be a ripped rubber boot on the slider pin that allows water to enter, resulting in rust. You probably will not be able to free the pin, as it will shear off if you try to force it back out with a socket. That is good, though, for at this point, you CAN drill out the remainder of the pin. Just be sure to use a new 11/32″ drill bit. It’s a long ream (3″ or so) but it will save you some money from buying a new lower caliper assembly. On the other hand, if you do wish to buy a new assembly, you will also need a new pin and boot set for these calipers (p/n E7SZ-2B296-A). They come with little packets of grease but you can just use regular bearing or high-temp grease to pack the new pins. Work out all air bubbles from the pin sleeves. After installing the new pins and boots, be sure to inspect the boots every oil change for any holes that could encourage water entry. This is about the only maintenance you need to do on a regular basis with this rear end, save for brake pad inspection.

If your brakes just won’t adjust right, or you get a locked-up caliper or two, that usually signifies that the rubber hoses going to the calipers have internally collapsed. This condition will let fluid to the caliper, but not back out, meaning a locked-up caliper. You’ll definitely need new hoses for the calipers (replace both at the same time) and then a re-bleeding ot the system. Please, above all, DO NOT attempt to lengthen the adjustable pushrod going into the master cylinder in order to increase pedal feel. Even one thread out from normal will result in too much pressure in the braking system, therefore locking up all 4 calipers in mid-driving. Trust us.



The piston in each rear caliper is a screw-in type; in fact, you will need to have them screwed in before you put new pads on. There are some rubber seals inside the piston chamber that rarely fail, but can, under extended use or repeated hard braking. If they fail, water again enters and the piston will rust inside the chamber. To fix this, you can purchase a piston rebuild kit from Ford (p/n E7SZ-2L128-A), and perhaps have a brake shop install it for you. In worst-case situations a new caliper may be needed, but a rebuild usually does the trick.



So after all this effort, the pedal feels a little lower now with rear discs than it was with rear drums?!?!? What’s up with this? Well, first you have to understand how rear discs and fluid correlate. A bigger bore master cylinder (like the one from the Crown Vic) provides a bigger reservoir of fluid for your rear discs, but less overall pressure; consequently, pedal feel suffers a bit. If you used your stock master cylinder, that gives you better pedal pressure while still having an adequate reservoir, although it’s not as generous as the Crown Vic one. So either way, there are advantages and disadvantages. Having done both, we opted for the Crown Vic master cylinder for the bigger reservoir. As long as you don’t have a fluid leak anywhere the stock master cylinder will work fine. But if you’re worried about fluid shortage, then the Crown Vic master cylinder is for you; you’ll just have to live with the slightly lower pedal feel. However, you can get better pedal feel back by installing stainless steel brake lines in the front. There are several companies that offer street-legal versions for the Mustang, including Russell, for the 11″ Mustang front rotors and the stock 10″ rotors. There is always the possibility that you may need a bigger brake booster to compensate. The 1994-95 Cobras provide a nice booster for us that fits rather well and greatly helps out.



Hear a whole lot of action going on in the rear axle area every time you hit the brakes? Believe it or not, it’s normal. Squeaking, on the other hand, means you’re either getting low on pads, or there is excessive glazing on the rotors. Since the rotors and pads are both organic, pad dust is attracted to the rotor, and with heat added, you’ve got a wonderful recipe for glazing. You’ll have a tough time removing the glazing with the rotor still on the car; it’ll have to be taken off. Easiest way to remove the glazing is with a soft wire brush or 150-grit sandpaper and brake cleaner. Together, the combination will zip right through that foul stuff. Don’t worry about roughing up the surface; the pads will actually like that better the next few dozen times you hit the brakes.



If you find some brake fluid puddles, or you’re low on rear fluid every time you check it, you obviously have a leak somewhere. The first place to check is the banjo bolts on each rear caliper. If the brass washer(s) were not properly crushed during installation, or if they moved off-center, that will create a leak. Best thing to do is remove the banjo bolt, install new brass washers, and tighten the bolt back up big time. If you’re not leaking from there, check the connections at the brake line junction. If nothing still shows up, check under the hood at all the connections by the master cylinder and proportioning valves. Still nothing? Blown brake line somewhere—sorry.

If you still are having some kind of problem that isn’t resolved by the notes above, just contact us and we’ll try to work it out.

5-Lug Rear Axle Swap


If you’re contemplating doing a 4-to-5 lug swap on your Cougar but really don’t want to mess with changing out your rear axle shafts, or maybe your current rear axle has seen better days, then a complete 5-lug rear axle swap is probably going to be a better deal for you.

Please keep in mind that there may be modifications necessary to your braking system in order to swap in a new rear axle, whether you’re keeping drum brakes or upgrading to rear discs. Always consult a professional if this job is bigger than you’re willing to tackle.


5-Lug, Rear Disc Brakes/1994-98 Mustang

Since the 1994-98 Mustangs and the 1985-88 Cougar/T-Bird basically have the same width rear axle, this is probably the most logical step. All mounting points are the same as what’s on your car now, making this a very easy swap. The V6 Mustangs had the 7.5″ rear end while all V8’s had the 8.8″, and all had at least a 3.08 gear. Keep in mind that all 1994-up Mustangs had disc brakes, but the rear rotors are solid, not vented. Only the Cobras had vented rear discs. To use a 1994-98 Mustang rear in your car you will need to install emergency brake cables from a 1987-88 Turbo Coupe.


5-Lug, Rear Disc Brakes/1999-2004 Mustang

The SN-95 Mustang had a brake upgrade across the board beginning with the 1999 model year. This was because Ford opted to use the independent rear suspension in the Cobra. Since changes were in order for the entire chassis, Ford deigned this the perfect opportunity to address the issue of better brakes. And since the track was wider out back for all Mustangs, this becomes a very viable solution for those wanting a bit more stability, or for extra clearance of those ultra-wide rims. We believe that this 1999-up rear is the same width as the 1984-92 Mark VII rear. The axle shafts are at least an inch longer from previous SN-95 Mustangs, that much is certain. Also, all 1999-up Mustangs had at least a 3.27 gear. You would need to install emergency brake cables from a 1987-88 Turbo Coupe.


5-Lug, Rear Disc Brakes/1984-92 Mark VII

The Lincoln Mark VII was a much heavier car than our Cougars ever were, even with ours fully optioned. Therefore its rear axle is a very beefy piece, and it’s also wider by about 1″ per side to accommodate a wider track for better stability. The Mark VII was one of the only older Fox cars to have 5-lug wheels so it’s the perfect solution for anyone wanting to get better brakes, gearing, a wider stance, and the 5-lug pattern in one shot. In general the Mark VII 8.8″ rear axle came with a 3.27 gear and 10.5″ vented rotors. Traction-Lok was an option though, so it’s not a guarantee; check the axle tag to be sure. And some early Mark VII’s even had drum brakes. Be sure you know what you’re getting first. Again, all mounting points are identical to your car now. You would need to install emergency brake cables from a 1987-88 Turbo Coupe.


5-Lug, Drum or Disc Brakes/Ford 9″

Long the popular choice with drag racers, the durable Ford 9″ rear axle is best suited for strip and heavy-duty street applications. “Bulletproof” is an understatement concerning these bad boys, and with any imaginable kind of component available (spools, gears, Detroit lockers, etc.), your budget is the only limit. In order to fit your Fox Cougar chassis, a custom-built 9″ is usually recommended, although a Mustang unit will usually fit very well. This is one area that’s definitely best left to a professional shop. If you’re tubbing out your car, the narrowing of a Ford 9″ should be no sweat for the pros.

Control Arm Upgrades (Front/Rear)

Your Cougar’s control arms (front and rear) are made from standard-issue OEM components designed for longevity. As vital suspension components, however, they just can’t handle any kind of serious performance driving. And let’s face it: with the advancements in Fox chassis performance suspension components in the last few decades, it’s really beneficial to upgrade your control arms to something much more modern.



The front A-arms have been a shroud of mystery for a lot of Cougar owners. Let us dispel the rumors: you have Mustang-style A-arms in your car, but it depends on your model year. Here is the conversion you need to know:

1983-86 Cougar/Thunderbird
1979-93 (Fox) Mustang
1987-88 Cougar/Thunderbird
1994-98 (SN95) Mustang

Stock Front Control Arms

Here is a side-by-side comparison. On the left is the shorter 1983-86 Cougar A-arm. On the right is the 1987-88 Cougar A-arm. Note that the later arm is 3/4″ longer and has revised points for mounting the springs and the sway bar end link. Because of the different types of stock engine crossmembers used in our cars, it’s not advisable to interchange one type of A-arm for the other unless you have replaced the engine crossmember (“K”-member).

The 1983-86 front A-arms used to be available new through Ford Racing (p/n M-3075-A). They featured brand new low friction ball joints and improved inner bushings. However, Ford Racing has since discontinued the kit. Remanufactured or new stock-type control arms should still be available via Fox Mustang websites, Rock Auto, etc.

The 1987-88 front A-arms, originally adapted from the rear-drive Continental, have a deeper cup for the spring seat, and a raised section for the ball joint. They allow for 1/2″ more travel vs. the earlier arms, meaning better control and ride. Ford Racing used to offer a kit (p/n M-3075-D), which would upgrade your A-arms to 2003-04 Mustang Cobra specs. Again, that kit is discontinued but we’ve seen them on Mustang restoration websites as well as Rock Auto.


Tubular Front Control Arms

For increased handling and better unsprung weight you can use tubular A-arms meant for Fox Mustangs. They greatly reduce unsprung weight in the front end and give you excellent cornering and control. While not very cheap, the prices of such pieces have come down in recent years and are close to being affordable for the masses. They are really intended to work with tubular K-members but sometimes can be used standalone, depending on the brand. Keep in mind that a lot of tubular A-arms will not allow a stock spring to seat; almost all use coil-over struts. Also, some tubular A-arms do not allow for attaching the stock sway bar. Shop carefully!



Your car has a live rear axle with traditional rear-drive 4-link suspension: two upper control arms and two lower control arms. Changing the control arms has a huge impact on how your car handles, and more importantly, how well your rear axle behaves during hard cornering and spirited driving. The stock control arms are 3-sided with an open bottom and can flex and bend under hard driving. While welding plates onto the bottoms will technically help strengthen them, that’s just a temporary fix. Full box tube aftermarket control arms are better, but tubular control arms offer the ultimate in strength and resistance to bending or warping.


Using Mustang control arms won’t work for us—we have unique-length upper control arms. Even adjustable Mustang uppers won’t give acceptable results. In the past we’ve had to resort to using GM A-body (Chevelle) uppers because they were close enough in specs to what we need (within .0040″), and they do work well. However, we can now use CHE uppers that are specific to our chassis; see below for more info.


It is possible to use Mustang-length aftermarket control arms on a Cougar/Thunderbird. They are about 3/4″ shorter, centerline to centerline, and therefore will rotate the rear end upward slightly, and shorten the overall wheelbase a small fraction of an inch. They’ll also increase the pinion angle slightly. While there seems to be no negligible effects of using them, most owners prefer to have the correct length control arms if possible. Fortunately we do have a few choices.


Rear Control Arms - CHE

CHE Performance contacted us in late 2004 with the willingness to accommodate our chassis’s control arm requirements into their in-house manufacturing. The result is a set of tubular steel control arms, both upper and lower, and the first such arms specifically made for the Fox Thunderbird/Cougar chassis in a complete set. The build quality is excellent, and fit and finish are outstanding. Installation is a breeze. All hardware is included with the kit as well—you don’t have to reuse any of your stock bolts. Their stock bushing is an interesting urethane/Delrin design for low friction and no squeaks. It’s a good compromise for the street and performance driving. CHE will custom make bushings to fit your driving—if you want a softer bushing for the street, or a harder bushing for the strip, not a problem. You can even have the housings powdercoated in one of several different colors instead of the stock silver finish. And you can get adjustable lowers and uppers for slightly more cost than normal. If you need to order just the uppers, CHE will do that for you. Please use the promotional code COOLCATS during checkout and receive an additional 10% off your purchase. We’d like to hear your feedback about these products as well. Please contact us with your observations.


Rear Control Arms - Maximum Motorsports

First on the market to mass produce specific lower control arms for our cars is Maximum Motosports, who is renowned for their Mustang race car wins, both factory-sponsored and individually-sponsored. Needless to say, they know what they’re doing when it comes to making killer suspension components. Owners have reported good-to-slighty-harsh ride quality, likely due to the harder urethane bushings used. Handling is markedly improved. All components are of excellent quality. MM offers a few options as well: stock-length tubular (MMRLCA-3.3), or adjustable tubular (MMRLCA-4) to help control ride height. Spring perches and sway bar mounts vary, so be sure to order the correct style for your particular application. Note: we do not believe that Maximum Motorsports offers a compatible rear upper control arm for our cars. They purport that some flexing is required in the rear suspension system and the stock uppers with rubber bushings are well suited for that task.


Rear Lift Bars - UMIIf you’re looking into serious traction bars for drag racing, the infamous South Side Machine lift bars really plant the rear end on takeoffs. They bring your rear suspension’s imaginary center of gravity to the dead center of the car (instead of a foot in front of your front license plate with the stock suspension). This results in less power lost in the suspension wind-up and more power to the rear wheels. They are not recommended for street use since they give a punishing ride—they are for drag-strip use only. SSM is now part of UMI Performance, Inc. and they offer the lift bars plus rebuild kits for them.

Shock/Strut Upgrades

When choosing a new high-performance shock or strut you have to factor in a few things, such as spring rate, driving habits, ride quality, and road conditions. For general performance and daily driving, a good aftermarket shock/strut is your best bet. Whatever brand you use, make sure it’s a quality name brand. You really don’t want to sacrifice the rest of your suspension by using inferior shocks/struts. Generally rear shocks will last longer than front struts and you may be able to get away with replacing them every other time you change the struts.



Mustang Coilover Kit

To coilover, or not coilover? That is indeed the question. By now you have probably heard of coilover conversion kits and may be interested in going that route. With a coilover setup, your factory springs are removed and your strut will be replaced or augmented with a coil spring setup, similar to newer vehicles. It’s an all-in-one setup that has a lot of advantages: adjustable ride height, compact components, the ability to run a tubular front suspension without penalty, and of course the improved ride quality.

By default, Fox cars run a modified MacPherson suspension. It is ‘modified’ because the springs are inboard of the struts and shocks. A true MacPherson suspension actually allows for coilovers but when the Fox chassis debuted in 1978 there was no practical way to create coilovers for these cars and have them affordably replaced. Today there is no issue for that, and both OEM manufacturers and the aftermarket have the infrastructure in place to handle a coilover suspension setup. So going with coilovers does not come with any sort of penalty, save for the cost.

So long as the strut towers are in good, solid shape then we have never found a reason to not use a coilover setup. Again, they are expensive but are the ultimate setup for cornering. A number of aftermarket Mustang suppliers have kits available. We would highly recommend getting kits for use with 1994-98 Mustangs as they are more compatible with our cars. Also keep in mind that this will usually require changing out your current struts and shocks completely, and that you will definitely need an alignment afterward.


Performance Struts/Shocks

KYB Strut

Now if you’re looking for high-quality performance shocks/struts or need the adjustable kind for things like road racing, remember that your shocks, struts, and springs work in conjunction with each other for absorbing road imperfections. If you have too stiff of a strut and your springs can’t handle that kind of load, then you’re in for a seriously harsh ride. You should only consider high-performance shocks/struts if you’re going autocrossing, drag racing, or have lowered the car over 1-1/2″. Also, it is recommended by some dealers that you use a stiffer strut with stiffer springs, as the spring rate on them is much higher than stock and will eat up even decent “normal” struts in less than a year.

There used to be a number of manufacturers that produced aftermarket performance shocks and struts for the Cougar and Thunderbird, but no longer. About the only one left now is KYB. They have a GR-2 model that should give you the performance gas-filled handling you’re looking for in most situations. We also like Bilstein for their performance and their lifetime warranty.

While we’re on this subject, we should probably address the 800-lb. gorilla in the room: Mustang shocks and struts. Since there are so many more aftermarket choices for Mustang performance shocks and struts, it’s very tempting to just use those instead, right? Well, yes and no. You can use them but you have to get the correct model years. Do NOT use 1987-93 (Fox) Mustang shocks and struts, no matter how tempting that may be, because they simply don’t have the right travel length (“sweet spot”) for rebounding and absorption that our cars require. You will have an incredibly bumpy and punishing ride as a result, with plenty of bottoming out. Instead, you can use SN-95 Mustang parts (1994-98) as their suspensions became alarmingly similar to our cars. There is still a matter of full shock travel not being perfect, but they are very, very close in spec and will bolt in with no modifications. Several readers are using them now and report no issues. If you cannot find a Cougar/Thunderbird-spec strut or shock combo that meets your needs then the SN-95 Mustang shock/strut combo should be the next place to look.


Air Shocks


Air Shocks

You may be tempted by the ubiquitous air shock, which uses air instead of your normal gas-charging to absorb the shock. You can fully select the pressure inside the shocks, something that you cannot do with most aftermarket shocks. However, there is again a tradeoff—a much firmer ride. And you also have to keep an eye out for air leaks. Once the air leaks out, you’ve got nothing inside the shocks to keep your back end up, and you can imagine what that feels like. Some people like them, some don’t. The fact is, it’s simply a temporary fix for keeping the back end up if you’ve got weight in the trunk or are towing. A cargo coil spring does a much better job than an air shock.

So in short…no, don’t do them. It’s not the 1970s anymore.


Quad Shocks

Quad Shock

If you have the factory quad shocks (a.k.a. axle dampers), local and online parts stores can get replacement quad shocks and they are rather inexpensive. You may have to look them up for a 1987-93 Mustang GT as sometimes their computers don’t list for a Cougar or Thunderbird; the Mustang parts are identical. Several companies do make a performance quad shock, but we really can’t say what advantage they’d be, since quads are so much different than a normal shock. When pulled one way, the quads do not compress back; instead, they stay put, hence the axle dampening name. They last a very long time but should be changed every other time you change the normal rear shocks for best performance. A new set of quads works miracles in keeping the rear end under control.

Spring Upgrades

Let’s face it: most stock Fox Cougar springs are made for mainly one thing–a cushy ride. That’s not a bad thing, unless you want the car to handle and corner better. Fortunately you can fix that situation rather easily with a new set of handling springs. Keep in mind that when we’re talking “handling”, we are also meaning that the springs will lower the car a bit. How much is really up to you—it can be as little as 1/2″, or as much as 2″-3″. Also, you have to remember that as the spring rate increases, so will the harshness of the ride. And with any drop of 1-1/2″ or more, offset steering rack bushings are pretty much a requirement.

You may be tempted to do things the cheap way (cutting coils from the stock springs, heating up the coils with a torch, using spring compressor-type lowering kits) but they will not be good, or safe, or permanent. In order to get a lowered car you should do things the correct way: installing new springs.

Note: this section is for those cars keeping the stock suspension setup. This is not intended for coilover conversions; see the Shock/Strut Upgrades section for details on that.


These are springs that will either keep the same ride height, or lower very modestly. For most people that want this look while using very good handling springs and maintaining a bit sportier ride, the 1987-88 XR7/Thunderbird Sport V8 springs, available through your Ford dealer or good parts stores, are probably for you. They have a revised rate over stock springs for better handling and give you a snappy ride without too much jounce. You can use these springs on all V8 cars from 1983-88. Ride is decent with great handling. They are the perfect blend of decent ride and decent performance for this chassis, already engineered by Ford for you. You can purchase new TRW/Moog V8 Sport springs under the following part numbers (thanks to Philippe, Troy and Bryan for the info):

  • Front coil springs, standard duty, constant rate, stock sport: CS8658
  • Front coil springs, heavy duty, constant rate, sport: CS8606
  • Rear coil springs, standard duty, constant rate: CS8599

You also have another choice: the 1987-88 Turbo Coupe springs. Yes, that car was a 4-cylinder, but the spring rates were really high. These springs make a good choice for both lowering your V8 Cat, but be warned: expect your car to drop at least 1.5″ all around, perhaps 2″ or more.



If you own a V6 Cougar, you already know that you shouldn’t use a V8 spring. This is because they will actually raise up the car and make handling very dangerous. However, you can use stock 1994-98 Mustang V6 convertible springs just fine in your car. Dimensionally and weight-wise, SN95 Mustangs are a lot closer to the Cougar and Thunderbird than any other car. Several people have reported success using these springs in their Fox Cats and Birds. An additional benefit is that you can usually find them dirt cheap at the salvage yard, swap meets or online.



The same SN95 rule applies to V8 Cougars as well. A set of stock 1994-98 Mustang GT springs will give a snappy ride. You can even use 1994-98 Cobra springs, which lowered that car about 1″ from the factory.

Clay has some information concerning the 2001 Mustang Bullitt. As you may know, the Bullitt had its own suspension components unique to the car. Any Ford dealer should be able to get them for you. The individual part numbers are as follows:

  • Front: 1R3Z5310CA
  • Rear: 1R3Z5560AA

You should probably use the matching shocks and struts with those springs:

  • Struts: 1R3Z18124AA
  • Shocks: 1R3Z18125AA

The stock 1995-up Mustang GT spring rates are 450 lb/in linear front and 210 lb/in linear rear, which is almost identical to the M-5300-D springs (see below). The Bullitt springs are 600 lb/in front and 250 lb/in rear.



For years we’ve been asked, “Do these things exist?” Well, yes they do…you just have to dig quite a bit to find them. Eibach used to make specific lowering springs for 1983-88 Cougars/Thunderbirds. Some people have reported that the kit requires some sort of strange modification to the car; we cannot confirm this. These springs are no longer produced; last production was in 2000. JC Whitney also occasionally sells a type of lowering spring; how it works is unknown, and it’s been out of stock for several years now.

It used to be that you could order lowering kits from Ford Racing. Two different kits were available: the M-5300-D (1983-86) and M-5300-E (1987-88). Ford Racing has stopped selling these springs as of 1999. You can really use either kit with any 1983-88 car; the spring rates were slightly different but not significantly so. The kit lowered V6 cars about 3/4″; for V8 cars, an easy inch or more. They were not recommended for turbo-4 cars though. Most people really loved these springs and they’re almost legendary. If you can find them, buy them!



If you just want to say goodbye to the dreaded sag while keeping the stock front springs, then we’d recommend what’s known as the cargo coil. It’s basically a heavy duty variable rate spring intended for towing, but it works great at keeping your back end up to proper ride height. Plus, the more weight you add to the car, the more the spring will try to force the car body up to correct ride levels. If you have a stereo system and/or subwoofer box in the trunk, these springs work miracles for you. Highly recommended. TRW/Moog part number is CC823.

Now if you tow a lot, there are aftermarket kits available that allow you to place an adjustable inflatable bladder inside the rear springs. With the on-board air compressor mounted, you can adjust the air bags to give you a floaty yet controlled ride while keeping the back end of the car at normal height. They work pretty good, and the kits aren’t all that much money either. Might be worth looking into even if you don’t tow. This can have an added bonus of giving you the “low-rider” look.

Along similar lines are the stock air bag suspensions from the Lincoln Mark VII/Continental. These air bags replaced the traditional coil spring and were auto-leveling from the factory via a microprocessor. Especially early on (circa 1984), there were many problems with air leakage, so be aware of this. With enough patience, it is entirely possible to swap out your suspension for this type of air bag support. Be prepared to run lots of air lines and wiring though. With a Cougar, an air bag suspension does sort of fit into the car’s image, so this would be a natural step for you should you decide to do it. You really won’t gain any performance handling with air bags; in fact, you’ll lose quite a bit. But you will get a silky-smooth luxury ride.

Last, the temptation may be there to use a 1979-93 Mustang spring. Physically they will fit and work. However, most people report very harsh ride quality, and some bounciness over road imperfections and bumps. These springs really cannot be recommended for the level of quality you’re probably wanting. Any of the other alternatives mentioned above will work much better than these springs.

Steering Rack Upgrades

The steering racks used on stock, non-sport 1983-88 Cougars have a constant 20:1 ratio, and that’s why you have to constantly turn the steering wheel while driving. They are approximately 2-3/4 turns, lock to lock, and are boosted quite a bit for low effort. Although the sportier cars came with a 15:1 ratio rack, those that weren’t so lucky will probably want to swap out to a steering rack that gives more input. Or if you are into this sort of thing, a manual rack could be swapped in as well. It all depends on your car’s purpose and your driving style.

NOTE: For those of you who may have carpal tunnel syndrome or arthritis, you may want to stick with the stock 20:1 rack for increased boosted steering assist.


Fox-Chassis 15:1 Power Rack

If you’re tired of the numbing feel given from the stock 20:1 rack or just want a better rack for more aggressive driving, then upgrading to at least a higher-effort Fox-chassis 15:1 rack is a good place to start. In fact, it’s probably the single biggest front-end improvement you can make, simply bolting in and requiring just over 2 turns lock to lock.


Steering Rack

The Fox 15:1 steering rack—technically a 14.7:1—can be found in the Cougar XR-7 (1984-88), Thunderbird Sport V8 (1987-88), 5.0 Mustangs (1986-93), and all Thunderbird Turbo Coupes (1983-88). Once it’s broken in, you’ll notice a huge improvement in steering (and you’ll find yourself going out of your way to find a really twisty road). The difference between the two racks is absolutely amazing. If your rack is shot, then the Fox 15:1 rack should be considered for a replacement.

It may be possible to get a new rack from Ford but it’s going to be expensive. On the other end of the scale, a remanufactured rack can be purchased at online and brick-and-mortar auto stores. Currently we are using a remanufactured Atsco 15:1 rack and it seems to be of decent quality. In the middle/high end would be aftermarket racks, such as those sold by LMR and Unisteer. Really it’s up to your budget but there is something available no matter what you can afford.

Since the steering shafts are SAE thread you can simply reuse your tie rods and accompanying jam nuts.


SN95-Chassis Power Rack

So several years ago we tried to install a stock 1994-98 SN95-chassis Mustang GT rack into our Fox-chassis car and let’s say it didn’t work out so well in the fitment department. Stock-for-stock, the racks are very different due to the geometry of the K-members. However, you CAN use an SN95 steering rack in a Fox car by swapping out a few components.

Why do this? Well, Ford improved a lot of things for the SN95 Mustang and the steering rack saw major late revisions to help with steering input. Fox racks can be rather…abrupt when quickly moving the wheel, and that’s an inherent quality associated with the Fox chassis. We’ve all come to know and expect this. But the SN95 racks got a touch of refinement in this area.

There are several different styles of later SN95 racks (about 7 at last count), so knowing which one you want is half the battle here. Apparently the 1994-98 racks are not much different than Fox racks, so it’s recommended to skip those. The 1999-2004 racks were set up differently for each car: Base, Mustang/Bullitt, Cobra, Y2K Cobra R, GT/Mach 1, etc. More on this below.

To use a later SN95 rack in a 1983-88 Fox car, you will need to swap out the inner tie rods to shorter Fox ones. Also, since the SN95 rack uses metric threads, you’ll need to swap over to metric tie rods (we are unaware of any SAE-style swapping here). And the steering shaft input on the rack is a different shape, so you will need a new steering shaft from the column to the rack.

Otherwise everything else is the same: K-member mounting bushings, hydraulic line connections, even the hydraulic pump pressure. It’s far from plug-and-play but at least some things are the same between the cars, making the swap a little less frustrating.

Fortunately the people at Maximum Motorsports have things figured out quite well with this SN95 rack swap and also carry the parts to do so. You will find much more information at this link, including which rack is best for your driving style and the type of steering shaft you’ll need for the swap. It’s also a great read and highly recommended if you’re considering the swap or just want to brush up on the information to make the swap.

Just FYI…as you might guess, this can be an expensive swap due to the juggling of components and need to buy multiple parts along with the rack. Be aware of costs before tackling this.


Manual Rack

If you are drag racing your car or want just want to eliminate power steering altogether in your car, you can use a Fox Mustang-oriented manual rack, such as those made by Flaming River. Occasionally you will find manual stock Mustang racks as well but they’re getting rarer these days. Remember that this is an extremely high-effort rack without power boost.


Power Steering Pump


Power Steering Pump

If you’re upgrading from a 20:1 to higher-effort 15:1 rack, you should also consider upgrading your power steering pump to match. There is a slight difference between the pumps, at least on paper. In reality, plenty of people have simply reused their old pumps without much issue. If there was some sort of serious problem then we’d definitely report it here; as of right now we’re not aware of issues.

Caster/Camber Plate Upgrades

Long a staple of Mustang performance handling, the aftermarket is finally waking up to the Fox Cougar/Thunderbird with caster/camber plates. In conjunction with lowering springs, the plates will give a much wider range of settings for getting your car back into alignment specs, plus allows for better tire wear. Plus, you can have one setting for street driving, another for the road course, and another for the drag strip. They are available for the Cougar/T-Bird chassis through just one company, Maximum Motorsports, and they retail for about $200 US a pair, which is comparable to Mustang units.


Caster/Camber Plates

One piece of advice: you must find a shop that can align the car using these plates. You will not want just anyone to do this for you. A complete set of specifications will come with the plates so that you can have the alignment shop easily get all your adjustment specs marked for you.

In case you’re wondering, the plates won’t really help much with a stock, unlowered suspension. They could help get a half-degree of camber or so, but that’s about it. If you want them just for looks or to say you have them, you’re not really spending money on something useful—you can get a lot more done to the car in other areas for the same amount of money.

Also, we’ve heard of several people that have modified Mustang caster/camber plates for their cars. While technically possible, they really don’t do justice to our unique suspension setup. Considering that the Cougar/T-Bird plates are the same price, it would be rather illogical to use them instead.

Sway Bar Upgrades

Most non-XR7 1983-88 Cougars did not come with a rear sway bar. Those that did (some V8 models) had a pitifully small one. And the front bar, while thick, can be improved upon. To make handling much better you can add (or change to) thicker sway bars. In conjunction with the 15:1 steering rack, a thicker front sway bar and larger rear bar will absolutely plant your butt in the seat during aggressive cornering. You’ll wonder how you ever drove without them. These bars will give your cornering the best bang for the buck and should be one of the first things you change in your front end.

For the front sway bar, the XR7/Turbo Coupe bar will work (any year, 1983-88). Or, you may use one from a 1987-93 Mustang 5.0 only, as they are the same part as the XR7/TC. You can usually find good, used sway bars easily at salvage yards or swap meets, or even online via eBay or Rock Auto.


Sway Bar End Links

Don’t forget about the end links. Traditionally you would never even give them a second thought until one of them breaks. However, replacing them with new, thicker links will make a big difference. And be sure to get kits with urethane bushings. In fact, make sure the sway bar main bushings are urethane as well. That is the best way to take all of the sloppiness out of the front end, and you will simply not believe the difference in handling with the addition of the new bar and all urethane bushings. Keep in mind that the XR7/TC/Mustang sway bar uses a shorter end link, so reusing yours is not really an option.

For the rear sway bar, the Turbo Coupe/XR7/Mustang bar works here as well. If you’re using aftermarket lower control arms, the location of the sway bar mounts is somewhat different than stock, meaning your sway bar will be lower to the ground and closer to the rear differential (pumpkin) cover. Be sure that you’ll have enough clearance while you drive. If the car is not lowered, you should not have any ground clearance problems with the relocated sway bar.


Rear Sway Bar

There are companies that make aftermarket sway bars. Most are lighter in weight, and some are set up specifically for drag racing, meaning that they’ll be less effective during cornering. There are even adjustable ones. The Ford pieces are definitely more plentiful and more affordable, that’s for sure, and coupled to a urethane bushing kit, they’ll hold up against anything out there. It just all depends on your driving habits, and what you need for your specific intentions (road racing, drag strip, etc.). For normal street driving, the OEM-type thicker bars are more than adequate.

Add a Pinion Snubber

Unlike the Mustang, the Cougar/Thunderbird chassis did not get a factory pinion snubber. This is essentially a rubber bushing on a metal mount that bolts to the underside of the rear floorpan, right above the rear axle. Its main purpose is to keep the axle from traveling upward during hard launches. This won’t add horsepower but will make the available power to the rear wheels more usable, thereby adding responsiveness to the car’s acceleration performance.

Pinion Snubber

While it may be tempting to use a factory Mustang unit, there is a big difference in floorpans between the two cars. The Mustang’s metal is significantly reinforced to handle the stresses of a pinion snubber; the Cougar is not. So that means you’ll just end up tearing the metal up really nastily. Besides, the unit does not fit very well. There are several aftermarket companies that make universal adjustable snubbers, so that may be an option. But until that metal is reinforced you’d just be ripping up good metal—you will need to get a plate welded in there first.

Frame & Structure Reinforcements

Ford’s Fox chassis was around for over two decades, and when the Mustang was beginning to become popular for hot rodders again in the mid-1980’s, the apparent weaknesses of the platform began to show up rather quickly. Not that it’s a bad platform; it’s rather good and tends to hold up well with time. However, as any motorhead will tell you, more is better. If you can stiffen up a chassis you’ll not only get a stronger car, but you’ll also get improvements to the ride and handling. Short of a full-out roll cage there are several ways to improve the functionality of the Fox frame. The following are great places to start.


Subframe Connectors


Subframe Connectors

Subframe connectors are excellent for helping to keep your underside together. They connect the points in the unibody “framerail” that are severed in production. Weld-on types are the most effective (while also being race-legal) and should be the only types considered. Bolt-ons will only create elongated holes with time and are not recommended. While people have also reported that Mustang units do indeed fit on the Fox Cougar, there are some pre-made subframe connectors made specifically from our cars from Global West. Or you can always make your own using square or even round tubing. After installation, be sure to paint up all the welds so they don’t rust.


Jacking Rails


Jacking Rails

Jacking rails work as a combination of outer rocker area braces and subframe connectors in one. While weighing in at around 30 lbs. each, the support that they give will benefit you greatly, especially on cars with a “colorful” history. Plus, you can place a jack under any part of the side of the car, and you’re safe to lift up the car. Note that the jacking rails pictured here have the seat cross braces; those are Mustang only and will not work on the Cougar/Thunderbird chassis. You can have custom seat braces made, however.


Strut Tower Brace


Strut Tower Brace

Long a popular item with Mustang owners, the strut tower brace connects both towers to the cowl, triangulating the engine bay with a stiff brace that keeps cowl flex down. You can use a Mustang brace under the hood of your Cat with minimal problems. Since the washer fluid tube is in a different spot in Mustangs, you may have to relocate yours in your Cougar to allow the brace to bolt into the cowl area. Or you can have a custom made brace. These are mainly for the 5.0 V8 cars, although the brace should clear the 3.8 V6 (both CFI and EFI versions). Braces for the turbo-4 must be custom made.


G-Load Brace

2-Point G-Load Brace4-Point G-Load Brace

The G-load brace (aka as the “K”-member brace) resides happily underneath the engine cradle for more underchassis support. In conjunction with a strut tower brace, this bar will keep the front part of the car solidly in place and will significantly reduce chassis flex. Fortunately, we’re in luck here: a Mustang-style brace will work. The engine mounting points can vary, but the K-members are virtually identical. There are 2-point and 4-point varieties available in the aftermarket; the 2-point are easier to put in, and are quite strong. The 4-point, on the other hand, are a bear to install, but will be even stronger. It seems that Mustang K-members are a little different than our cars at the mounting point area, and you may need to heat up and bend the G-load brace slightly to fit the Cougar/Thunderbird chassis.


Torque Box Plates


Torque Box Reinforcements

Torque boxes are located just in front of the rear wheels underneath the car. The lower control arms (from the rear axle) bolt into the torque boxes…and therein lies the problem. With added torque to the rear axle, the chassis tends to flex and when too much stress is evident, it has to release its energy somewhere; the torque boxes are usually the first to suffer the consequence. They will tear and separate along the sides and bottom. All Fox torque boxes are about the same, and there are a few Mustang-oriented products that specifically address strengthening torque boxes. This requires removal of the lower control arms, as well as welding, but it’s well worth it. Look at it as insurance for the future power you’ll be shelling out back there. Even simple welded plates over the bottom of the box will help.

You can get torque box plates specifically intended for our cars over at


Panhard Bar


Panhard Bar

A Panhard bar helps keep the rear axle planted by bolting into the frame/floorpan. The side-to-side motion of torque to the rear axle is severely curtailed by these bars. Currently there are several available for the Mustang. Since the upper control arms from the Cougar and Mustang are different, a Mustang-spec Panhard bar setup may not work. There are universal bars available that should work adequately, available from aftermarket mail-order companies.

From what we understand, it takes a LOT of work to get a Panhard bar to work in a Cougar/Thunderbird. It’s because of lack of clearance in key areas. Also, your exhaust system may need to be highly modified; it may not jump over the rear axle anymore with a Panhard bar in the way. Some people have opted for side exhaust, dumps before the rear wheels, or a modified/oval single exhaust pipe.

5.0L V8 - Dual Exhaust Upgrades

Somewhere it’s an unwritten rule that if you have a rear-drive V8 American car, it must have dual exhaust. That’s just the way it is. So if you’ve got a 5.0 engine in your Cat or ‘Bird, you’re probably thinking about putting a dual exhaust setup on the car. Considering that our car is generally a big Mustang, it would make sense that a Mustang-type dual exhaust will fit on the Cougar, right? Well, yes; in fact, you can use the entire system on the Cat with a few minor tweaks here and there. Rest assured, no matter what anyone else tells you, you WILL be able to put dual exhaust on your Cougar.

But where to start? Should you go with a stock Mustang system? Or what about the off-road and high-flow H-pipes? Or the newer X-pipes? Or should you just have a custom system bent for the car? These are some serious questions that you have to figure out on your end. Once you do, read on below to see what you’re getting into first. Whether you’re on a budget, or want the absolute best, or want to strike a happy medium, there’s a section below that will fill your needs.

Before you haul off to buy parts, there are a few things you need to understand about your car first:




Transmission Crossmember

A lot of Cougars and Thunderbirds from 1983-88 have the “double-hump” transmission crossmember from the factory. This crossmember is so named because it has the two humps necessary to clear a dual exhaust system. Some cars only had the single crossmember, meaning it won’t work with duals. Be sure to crawl under your car and check the passenger side of the crossmember to be sure that it’s got the hump and is not flat. Should you need to purchase a dual-hump trans crossmember, any 5.0L V8 Mustang from 1986-93 can provide one. Additionally, Ford Racing does sell them new (p/n M-5059-A) and you can purchase one through Jeg’s or Summit Racing.

Thanks to Sean for the part number.



Since no 1983-86 car ever left the factory with duals, there are a few anomalies with putting duals on that body style. The fuel filter (and depending on the model year, the external fuel pump) is located on the rear frame rail, passenger side, right in front of the rear axle. Exactly the spot where the passenger muffler goes, naturally. So you’ll need to a) reroute the filter and/or pump, b) run a skinny muffler, or c) live with the passenger muffler hanging down lower than the driver’s side. You will need to crawl under your car and determine the best course of action.

Some people have converted 1983-84 cars from a dual fuel pump (lower pressure inline “puller”/higher pressure in-tank “pusher”) configuration to a single high pressure in-tank pump setup, similar to those used on 1985-88 cars; this will help get rid of the obtrusive external pump and allow plenty of clearance for the passenger side muffler. However, if you don’t want to do all of that work (and believe us, a fuel tank change is not fun) then you can either use a very skinny muffler or dump the exhaust in front of the rear tires. There’s very little room for clearance over there so caution is a must.

In moving the fuel filter on 1985-86 cars, it is perfectly fine to simply move it up toward the front of the car, about 6″-8″. This will allow clearance for the passenger side muffler. While the muffler is still a really tight fit, it helps out very much indeed. Or, you can relocate the fuel filter outside the subframe rail with relative ease—there’s usually enough slack in the fuel line there to do it.

Additionally, there are no factory hangers for the muffler or the tailpipe on the passenger side. You can use stock Mustang or 1988 V8 Cougar/Thunderbird hangers, if you wish. Problem is, if your new exhaust kit comes with the hangers pre-welded onto the tailpipes, the hanger will hit the fuel filler neck on the passenger side. Not a good thing; in fact, it’s extremely dangerous. This will necessitate having the tailpipes lengthened to clear the filler neck. But then where do you hang them? We’ve used universal hangers with fair success. With a little creativity you can come up with something.

Finally, you will need to take special precautions to make sure that a passenger side muffler will not burn a hole in your lines, filter, or the fuel pump housing. Header wrap or other high-temp foil padding are highly recommended!


For the 1987-88 Cougars, Ford did some rerouting of the brake and fuel lines, as well as a relocation of the fuel filter to the outside of the framerail, so putting in duals is a lot easier. Provisions for dual exhaust were built into this body style. If you’ve got an ’88 with the factory duals, and are ditching the split Y-pipe for an H- or X-pipe, you’re in excellent shape.



All V8 Cougars have factory cast iron exhaust manifolds. A stock or aftermarket H- or X-pipe will not bolt up to the factory cast iron manifolds without fitting and leaking problems. So when you’re planning your dual setup, you must take this into consideration.


Factory 5.0L Headers

The easiest option to get around this is using the lightweight factory headers from a 1986-1995 Mustang 5.0L motor. Honestly, most Mustang guys would be just as happy to throw them away. Therefore you can probably pick up a set for next to nothing. Using these factory-style headers is also a great guarantee that any aftermarket Mustang exhaust will bolt right up.

Or you can go with aftermarket headers, pocketbook permitting. There are two basic kinds of small-block Ford V8 “shorty” headers: equal length and unequal length.


Unequal Length 5.0L Shorty Headers

If you’ve got the stock 140-150hp motor, or have converted to HO and are running the stock HO setup, and you will not be doing any other future motor work, it’s recommended to use 1-1/2″ unequal length headers in conjunction with a 2″ or 2-1/4″ exhaust system. Unequal length headers are much easier to install than equal lengths while still giving a tuned sound. On these cars, there will be little-to-no modification of the tubes for any clearances around the block.


Equal Length 5.0L Shorty Headers

Any motor over 225hp, or using radically-worked heads, should use 1-5/8″ headers. Equal-length headers (the ones that look like a bunch of twisted tubes) can be used for higher-horsepower engines, although getting them to fit is sometimes difficult. There is usually an issue or two around the oil dipstick tube, or even a motor mount, and provisions will have to be made to get them to fit. However, the payoff for equal-length headers is better low-end torque and a wonderful tuned sound. A word of caution: getting equal-lengths to work with a column shifter setup is painfully difficult.

For more radically modified engines there is always the 3/4-length or full length exhaust header. Installation of either will virtually require a T-5 manual transmission; although we do know of a few cases where they were modified to fit around an AOD casing, that is exceptionally rare and costly. These headers are typically used for race cars and are not terribly practical for the street.

One last thing to remember about aftermarket headers: they are designed for an engine, not the compartment where the engine resides. You may have to move, bend, tweak, cut, or modify something around your engine to get headers to fit. That is the nature of hot rodding but please be patient, as the rewards are worth all the effort.



Another annoyance has to do with your gear shifter. Most Cougars came with the column shifter from the factory, and only XR7’s and optioned-out cars got the floor shifter. The column shifter uses a whole bunch of rods and linkage right around the driver’s side exhaust manifold to connect to the transmission. For this reason, no matter what automatic transmission you’ve got (AOD, C5), your linkage will present a problem with the exhaust system on the driver’s side. Using the stock Mustang headers is a great choice here because they usually clear everything just fine. But you will definitely have to watch with the O2 sensors (see below). For an AOD with the column shifter, you can usually get the O2 sensor to fit between the linkage with no clearance problems. You may end up rearranging some linkage a bit, but it will work. Other transmissions may also have a similar solution. Best thing to do is measure everything and make sure you’ll be okay.



Now with the floor shifter, there’s another unique problem. The bracket that holds the kickdown cable (aka TV/throttle valve) on the transmission hangs down just enough to interfere with the H-pipe. You will need to grind down the bracket approximately 1/2″ to get the H-pipe to fit right. There is nothing more annoying than having the H-pipe squeak every time you hit a bump! For all transmissions alike, please be aware that the factory H-pipe with 4 catalytic converters comes really close to the kickdown linkage on the driver’s side of the transmission. If you’re not careful with clearances in this area, your kickdown cable can get stuck on the top of the converter and you’ll experience some nasty shifting. This is not a safe situation. Our advice: remove the heat shield surrounding that particular converter (the smaller one, toward the front) before you install it. That should assure you of no clearance problems in that area and it won’t affect the performance of the converter.




O2 Sensor Extension Harness

When replacing the exhaust manifolds, you are also removing the oxygen sensors (aka EGO, HEGO, O2 sensors). For any computer-controlled engine, especially with Ford’s EEC-IV system, you CANNOT run the vehicle without O2 sensors in place, or else your fuel economy and performance will suffer greatly. You can also cause severe engine damage so please, do not even think about letting them hang or disconnecting them. So what to do? Well, MAC makes aftermarket headers for 1994-95 5.0 Mustangs that have O2 sensor provisions. That would be the most practical solution. But most of the time they go in the H- or X-pipe, downstream from the motor a bit. All aftermarket and factory H-pipes have provisions for O2 sensors, essentially a bung with a 15mm thread. You can either lengthen the wires on your existing O2 sensors (if they’re newer), or you can get the longer O2 sensor wiring harness from a Mustang that will bring the wires down closer to the H-pipe. That’s a nice little salvage yard piece, or it can be bought new from IST. If you need new sensors anyway, Bosch sells new sensors with varying lengths of wiring, so you can probably just use those and keep your stock O2 sensor harness. Now you will have to watch the connectors on the O2 sensors, as there are different types. Best thing to do is take your old ones to the parts store and compare the ends with the new ones. If you are putting your own O2 sensor bungs in a new pipe, you will need to place them on the bottom side, before the crosspipe (the “H”).




5.0L H-Pipe

This is what makes true dual exhaust dual, and what most people think of when you picture a Mustang-style dual exhaust. For a used H-pipe, try to find one that has had all 4 of its catalytic convertors replaced under factory recall. As you may guess, it’s very expensive to replace all the cats. For a new H-pipe, aim for a 2-1/2″ setup with 2 high-flow converters, or an off-road H-pipe if legality won’t be an issue.




5.0L X-Pipe

The X-pipe is a relatively newer idea for passenger cars. Long used by NASCAR, it equalizes the pulses from the motor better than an H-pipe. This results in a significant horsepower increase (usually between 10-20 or more for just the X-pipe alone), as well as a very strong and very different exhaust note. You can get an X-pipe with high-flow converters or without any converters at all. If you need low-end torque, the X-pipe would probably not be a wise choice. Still, if you want something different, the X-pipe is for you.



When purchasing a cat-back Mustang exhaust system, you’re confronted by a few choices, and most of the time it usually revolves around how much you have to spend. For all practical purposes it is not wise to reuse an old Mustang exhaust, no matter how tempting. You’re much better off in the long run with a new system. Besides, there’s nothing like putting on brand new parts. So at the very least, you should purchase an aluminized system. These are the cheaper of the two kinds of kits, and provided you don’t bang up the pipes too bad, they’re good for roughly 7-10 years of rust-corrosion resistance. Not a bad investment at all. Some of the more popular brands are Flowmaster, Dynomax/Walker, and Thrush. Each kit will fit very differently, but all do pretty much the same job.

On the other end of the spectrum, there is the stainless steel exhaust kit. The most widely known stainless kit is made by Borla, although there are a few others coming into the picture now. Now these kits are really wicked and install like a dream, but they’re frightfully expensive, and usually out of the reach of most people. However, the trade-off is that they will never rust. It’s quite literally the last exhaust system you’ll ever buy for the car.

Also, you can’t forget about tube width. Most places will stock 2-1/4″ pipe, and should have 2-1/2″ pipe, the two sizes that are the most popular for a Ford 5.0 motor. But width will depend on your power output—bigger is not necessarily better. If you’ve got a stock 140-150hp 5.0, then you’ll want to go with the 2-1/4″ pipe. The advantage over 2-1/2″ pipe is that it fits much better, so less chance of rattling around. Anywhere from 200hp and up, the 2-1/2″ system is best for optimum flow. Ultimately, you must decide for yourself what is the best and most cost-effective for you, and make the best decision you can from there.

Now since our cars have quite a bit more body after the rear axle than a Mustang, the tailpipes may need to be lengthened a bit around the fuel tank. This depends upon if you really want them to look good or not. If you’re not really concerned about the looks, then a shorter tailpipe won’t hurt you a bit. Mustang LX tailpipes are generally longer than the GT pipes.



We’ve had several people report that their custom exhaust systems cost less than the cheapest aftermarket kit. That’s a significant savings! But in order to find out if this is cost-effective for you, you will have to do a little research in your area. Mainly you’ll have to call or visit muffler shops and find out if they can do this for you, and also to get some pricing. Then simply weigh them all against each other. But first you must arm yourself with some understanding and knowledge of what you’re about to get into.

Exhaust systems can be made from 3 different types of steel: regular, aluminized, or stainless. All 3 types will carry a different price, and you have to know this going in. Regular steel exhaust systems are very cheap, but they will also need replaced every 2-3 years. Not just the mufflers—the entire thing. This is not usually the most cost-effective way to go, although the price factor could be tempting. Now an aluminized system takes the same gauge steel tubing and adds an aluminized coating to it. This greatly enhances the metal’s rust-preventive properties. In fact, the average aluminized system lasts for 7 years! And the plus side is, it’s not much more than plain steel. If you are going through the trouble to put a custom exhaust on your Cougar, please do not consider using anything less than aluminized tubing, or else you will simply be throwing your money away. Now this usually does not include aluminized mufflers—they’ll still have to be replaced every few years, more than likely, unless specified by the manufacturer. Since exhaust systems rust from the inside out, it’s almost impossible to offer a warranty on aluminized mufflers. The third type of exhaust system uses stainless steel. This is the same type of steel used on your silverware, and it’s known for its excellent rust-fighting properties. Stainless exhaust systems are the cream of the crop for this fact. And that also means it’s the most expensive. Stainless pipe is much thicker, requires special cutting tools, and must be bent while packed with sand or similar substance. You can see now why it costs so much. But the tradeoff is that this will literally be the last exhaust system you’ll ever buy for your Cougar (barring accidents, of course). You will pretty much never have to worry about rust eating through the pipes. You will never have to worry about replacing stainless hangers (if they are used). And the finish usually stays shiny and metal-looking for years. This is THE best you can get. So the type of steel used in your custom exhaust system will have a big impact on your wallet.

Before you go taking in your parts that you just bought to the local muffler shop, please check first and make sure that they will install your parts. Some places don’t like when you do that to them. If you’re allowed to bring in your own parts, and they’ll hang them for you, then you may want to look for some mufflers. Not just for performance, but for sound. Let’s be honest, the sound factor is half the reason why you’re putting duals on in the first place. (The other half is seeing that other pipe hang out the passenger side). So you may as well go for some great sounding mufflers. The major exhaust companies (Borla, Flowmaster, Walker/Dynomax, etc.) do indeed sell their mufflers separately. If you’ve never heard any of them, talk to a few Mustang guys or hot-rodders. They can give you great input on which ones to get, according to sound. Where do you buy these parts? Best place to look is a high-performance parts catalog, such as those by Summit Racing or Jeg’s.




H-Pipe Hanger

The hooks on top of the H- or X-pipe are for hanging the pipe onto the transmission mount bracket—make sure you do this! You might want to pick up the double-type mount from a Mustang and put that on; however, your stock single-type will work adequately if you can’t find a double mount.

There is an air tube on the H-pipe that you can’t forget about. It’s hooked into the Thermactor air system on the car. The air pump (driven off the car’s fan belt) feeds fresh air to the heads and the exhaust. This H-pipe air tube is where the fresh air comes in; its basic function is to allow the catalytic converters to receive oxygen so they can catalyze better. The air tube runs between the H-pipe and the junction under the hood, on the passenger side, right next to the header in the rear of the compartment. If your air tube is broken or missing, it is acceptable to run a good quality high-temp hose between the H-pipe and the junction, provided you clamp the hose down accordingly.

We’d also recommend using the new-style band clamps for the entire exhaust system instead of traditional clamps, if possible. They look awesome, provide a 360 degree seal, and are stainless steel for long life. If your exhaust system is aluminized or stainless, or you’re looking for a leak-free and permanent system, then have all the joints and seams welded.



Depending upon where you live in the US, there can be some rather strict laws against modifying your exhaust system. Emissions being what they are today, we would strongly suggest that you contact someone in your state’s BMV about your proposed plans to change the exhaust. Some U.S. states, such as California, allow nothing over and above what came with the car for that model year. So please keep this in mind. Any item that says “49-State Legal” or “50-State Legal” is what you’re looking for, because that means it passed stringent U.S. government testing.

3.8L V6 - Dual Exhaust Upgrades

Anything you can do to help free up power in your 3.8L V6 is a plus. Aside from a K&N filter and hotter spark plugs, you’re probably thinking of going with a dual exhaust setup. That’s a good move since less restriction will free up much-needed horsepower to the rear wheels. There are several ways you can go, but in all cases you will be gaining real-world, usable power. You have to consider a few things first, though.


Fuel Filter

Owners of 1983-86 Cougars are faced with the fact that the car is not set up for dual exhaust. The main stumbling block is the fuel pump and/or filter, right exactly where the passenger side muffler needs to go. This is a major situation. If you can have a repair shop relocate them for you, that’s a great start. Otherwise, you may be forced to use the only mufflers that can fit alongside the factory filter/pump location: Cherry Bombs. Still, they will fit without modification. Owners of 1987-88 V6 Cougars should not have to worry about that, since Ford put the filter outside the framerail.



You’re also cursed just the same as 5.0 owners with the stock cast-iron exhaust manifolds. They are what really keep the power output down. Replacing them with headers is the best thing you can do to gain power and free up airflow restriction.

3.8L V6 Headers

You can use factory 1994-98 Mustang headers as they are stout pieces; the same basic headers are also found on 1989-97 V6 Cougars and Thunderbirds. They will also help provide a more aggressive tone to the exhaust system and fit fairly well.

3.8L V6 Headers

MAC makes V6 1-5/8″ shorty headers for the 1994-1997 Mustang (part number TF3845) for around $230 US. Note the air tube sticking out from each one. You do not need this for a 1983-88 3.8 V6 on your Cougar, and will need to plug up the holes or have them welded shut. These shown are for the 1999-up Mustang; buying a 1994-97 part may eliminate those holes.

3.8L V6 Headers

MAC also makes 1-5/8″ long tube headers for the 5-speed 1994-1997 Mustang, part number TF3895, for around $250 US. Note that these headers will not clear an AOD transmission casing. Thanks to Chad for the info.

Jay reports that if you have a column shifter, the linkage gets in the way and must be moved. The exhaust pipes that bolted to the factory manifold need to be opened a 1/2 inch, rebent and shortened slightly. You’ll also need to make a new EGR tube and find a fitting for the header’s EGR nipple. You will have the same oxygen (O2) sensor relocation problem as 5.0 owners. There are ways to solve this problem—read on.



The first thing you need to do is determine how far you want to go with duals. Do you want just a little more power, or do you want the most you can get? Your budget will probably have a large influence on that. If you can’t swing much cash then you will probably be best to stick with your stock exhaust manifolds and Y-pipe. You can have a secondary Y-pipe custom bent from there to go into your mufflers. This is a nice, clean installation and is very efficient since you’ll just reuse part of your factory system. If you’re going all out though, you’re going to want an H-pipe. The easiest way for you to get an H-pipe for your V6 is to get one from any 1987-95 Mustang 5.0. Yes, it fits, although you may have to get it slightly re-bent to fit up to the headers/exhaust manifolds (whichever you decide to run). The H-pipe will have the bungs installed for the O2 sensor(s). If you just have one sensor then you need simply to plug up the other hole in the H-pipe with a 15mm bolt and some Teflon tape. You may also need to lengthen the wires for your O2 sensor. Once that’s settled, you can run your cat-back exhaust.


Pipe Diameter

It is recommended that you use a 2.25″ exhaust system for the V6. Anything larger than that is overkill and may even cause a slight hesitation. Obviously the driver’s side will fit nicely; the passenger side will need to have universal hanger installed for the muffler and tailpipe. Now there are two ways to get a cat-back exhaust: either custom bent or aftermarket. Custom bent duals insure that the fit is excellent. You will get exactly the length of pipes that you need, meaning less chance of an exhaust leak. This is a big plus. The downside is that it may cost you more; however, the quality alone is usually worth it. If you decide to buy a cat-back system you’ll need to order it for a Mustang 5.0. The LX pipes will be longer and are recommended for a better fit around the gas tank. You may still need to have new intermediate pipes made (between the H-pipe and mufflers) due to the longer wheelbase on your Cougar versus the Mustang. Since each kit fits differently, you’ll have to experiment and see. Some of the popular brands of cat-back kits for Mustangs include Flowmaster, Dynomax and Borla. Each has its own sound and quality of finish, so you may need to do some homework in that area. In any case, you’re going to get a really nice system for your car that will free up much-needed power.

You can see that this is not a job for the beginner. In most cases you will probably need to have a muffler shop do at least some of the work for you. The biggest concern that shops usually bring up is that from their point of view, a tailpipe won’t fit on the passenger side around the gas tank. No matter what they tell you, it WILL fit—there is plenty of room for it. Besides, Ford was able to get a pipe on that side with the 1988 5.0 exhaust without any fuel tank changes, so that should help persuade some shops. Also, don’t be afraid to shop around for price quotes. Be sure to ask about the type of pipe to be used. If you are going through the trouble of having a custom-bent system, do not settle for less than aluminized pipe, which lasts 5-7 years or more. When all is said and done, you will have a very nice sounding exhaust system and much more off-the-line power.

3" Single Exhaust

If you can’t exactly swing the cost of a full dual exhaust, or it’s not legal where you live, or you just want something different, then a large single exhaust system may be for you. Large single systems are not unheard of: Pontiac briefly experimented with a large single exhaust system as recently as 1998 on the WS6 (Ram Air) Trans Am. The main advantage of a single system is that obviously, you don’t have to run pipes down the passenger side. If you are fearful of moving the fuel filter and/or pump, this is a big plus. You can simply use your stock hangers on the driver’s side. The larger pipe provides for a greater flow as well. While it doesn’t equalize the exhaust pulses like a true dual system does, it is still a giant leap from the restrictive stock exhaust system.

Now you will have to address the situation up front before you do anything—specifically, the headers and Y-pipe. To get any appreciable gain from exhaust modifications, you will need to install some type of headers, simple as that. For the 5.0L V8, even stock HO Mustang headers are better than the stock Cougar ones. A lot of people are opting for unequal-length shorties because they fit very well and provide good airflow. Equal-length headers are more of a pain to install but will give you a few more horsepower and a throatier sound. For motors 225hp and under, the 1-1/2″ headers are recommended. Over 225hp, you can use 1-3/4″ headers safely. One big problem for most 5.0 owners is the fact that the oxygen (O2) sensors are screwed into the factory exhaust manifolds. Obviously with their removal, the O2 sensors have no place to go, but you need them in order for the computer to function correctly (and to maintain good fuel economy). MAC does make headers for the 1994-95 Mustang 5.0 that have O2 sensor provisions, so that will take care of that. But if you’re looking to have a bigger Y-pipe made, then you may be able to get O2 sensor bungs installed downstream by the muffler shop. This would allow you to use any type of headers. A spark plug chaser has the necessary 15mm thread to mount an O2 sensor, if that helps you. It’s your call; fortunately you do have choices.

The Y-pipe, on the other hand, will have to be custom made. It may be worth your while to check into what’s legal as far as Y-pipe mods go. The reason is, you may be able to have your smaller pre-catalytic converters dumped and use just one single high-flow converter. This will greatly free up horsepower and offer less restriction. If you’re going through the trouble to have a bigger Y-pipe made, go no less than 2.5″ in diameter. It should mimic your stock Y-pipe in general shape so that you can drop the transmission pan for your fluid/filter changes. From there back, it should be a simple installation. You can choose any type of muffler you desire. The tailpipe will probably be expensive because of all the custom bends. It is very difficult to make all those bends and still keep the pipe from banging against the floorpan. Still, even a 3″ pipe fits comfortably. Remember, if the Mustang guys can do this, so can we.

(Note: If you have a turbo-4 Cougar or Thunderbird and are interested in building a custom large single exhaust system, please see the NATO website for more in-depth information).


3" Single Exhaust

This photo was provided by Jeff, who installed a single 3″ exhaust system on his Thunderbird. He used a Flowmaster muffler with a 3″ tailpipe and 3.5″ chrome slash tip.

10"-to-11" Front Brake Upgrade (4 or 5 lug)

All 1983-88 Cougars (and all Thunderbirds save for the 1987-88 Turbo Coupe) had 10″ front rotors from the factory. They’re pretty dependable, cheap to replace, and generally wear very well. But for all of their positives, they were barely adequate enough to stop cars of our heft. We really should have had at least 11″ front rotors, particularly on later (and heavier) Cougars. Fortunately you can upgrade to 4-lug 11″ front brakes with very little effort. All you will need to change are the spindles, calipers, brake lines, rotors, wheel bearings, and the brake pads.

Words of caution here: only cars with 15″ rims and bigger can use this conversion, since they need to clear the calipers. And you will need to get a bigger mini-spare tire from a Turbo Coupe or Mustang V8. If you’ve got a full size 15″ spare, you’re all set.


You will need the following parts from a 1987-88 Thunderbird Turbo Coupe or 1987-93 Mustang V8, except where noted:




11-Inch Brake Spindle

You can use spindles from either the 1987-93 V8 Ford Mustang (GT or LX) or a 1987-88 Thunderbird Turbo Coupe; they’re both the same parts. You can get them used at a salvage yard or online. The 1984-92 Lincoln Mark VII spindle will fit but requires modification of the ball joint attachment hole—avoid it. You will be able to reuse your struts, provided that you add spacers between the strut and spindle. This is because Mustang-spec 5.0 LX/GT struts are narrower where they meet the spindle, so using a Cougar/T-Bird strut will require spacers to properly work. Usually you can use a few washers to safely shim out the space (note: a lot of aftermarket struts actually come with spacers for just this purpose). We don’t recommend simply tightening down your existing strut with an impact gun and no spacers—that can lead to the struts slipping, and cause major headaches the next time you need to remove the strut from the spindle. Please use spacers, or if you wish, you could just buy a pair of Mustang-spec 5.0 struts and install them. (Sometimes replacement stock struts will come with spacers as well).




11-Inch Brake Caliper

You will need brand new calipers for this conversion; don’t skimp and try to use junkyard pieces. They’re best for using for a core when you get new ones. Remanufactured calipers are fairly inexpensive and cost-effective. Again you can use calipers from a 1987-88 Turbo Coupe or 1987-93 Mustang V8. The Mark VII is a much heavier car than a Mustang or TC, with the same size front brakes. As a result, the piston in the caliper for a Mark VII is bigger (73mm) vs. the Mustang/TC piston. This provides better stopping power, while still using the same caliper, dimensionally.


Brake Pads

Whichever caliper style you choose you must be sure to get matching pads. You cannot use TC/Mustang pads with a Mark VII caliper, nor vice versa. Factory pads were semi-metallic and that’s the least you should get (not organic!). Aftermarket pads have all kinds of choices now. We’re big fans of any pad that reduces brake dust. Choose a good quality pad and you’ll be set for a long time.


Caliper Bolts


11" Brake Caliper Bolts

You will also need new caliper bolts to go along with your new calipers. They are a different type than your stock ones, and new bolts will have a hex head compared to your Torx-bit round head type, so there is no way to reuse your old ones. You will have to generously grease up the sliding portion before installation. Be sure to also get new banjo bolts and crush washers for the brake line attachment before installation.


Brake Lines

The brake lines going to each caliper will need to be changed. If you want a stock part, Mustang lines work the best here, although the TC and Mark VII lines are probably the same thing. Compared to your old rubber lines, the new ones are about half rubber, half metal. This ensures better fluid pressure going to the caliper and also increases brake pedal feel. If you’re really wanting a harder pedal feel for not much more money, then you can also use DOT-legal stainless steel brake lines meant for a Mustang V8 (Russell is the common brand). Don’t forget to get new brake (a.k.a. “banjo”) bolts and washers to attach the lines to the calipers.


Brake Line Adapter

You will also find that you’ll need some adapters to get the new lines to attach to your car’s permanent brake hard lines. This junction is in the strut tower area. Most of the time a 1/4″-to-3/16″ adapter is needed, but you will need to double check this, as some years and models may have different sized brake lines. It’s recommended that you use a steel adapter rather than a brass adapter, as brass has a tendency to leak. Adapters can be found at good parts stores including NAPA.




11" 4-Lug Rotors

Only rotors from a Mustang V8 or Turbo Coupe will work for 4-lug wheels, since the Mark VII uses 5-lug. DO NOT use original Ford 11″ rotors, no matter how good of shape you may happen to find them. The factory rotors were very thin and needed replaced quicker than normal. It’s always a good idea to use new, quality brand rotors anyway. Prices range from roughly $60 US each on up, depending upon where you shop. The Turbo Coupe rotor should have the ABS exciter ring on the inside of the hub, and the Mustang will not. There may be a price difference between them; as you won’t need the exciter ring it’s likely cheaper to buy the rotor without one.


Wheel Bearings

It’s necessary to get new inside wheel bearings (the ones that go in the back side of each rotor), so it’s a good idea to get new outside bearings as well. If you have just bought new outside bearings for the 10″ rotors, you can reuse them on the 11″ rotors if you’d like. But new bearings are cheap insurance. If you still have factory nylon bearings (yes, those existed!) then now is the time to upgrade to steel bearings. Be sure to get new seals also.



From the factory between 1983-88 there are two types of master cylinders:

1983-86 Master Cylinder

The traditional cast-iron type (1983-86) had 2 separate reservoirs for the fluid (front and rear), and two brake line ports (one for the front, one for the back). This type has a 7/8″ bore.

1987-88 Master Cylinder

Beginning in 1987, most Ford vehicles switched to the aluminum type. Only one single plastic reservoir was needed, and brake pedal feel was increased due to its larger 1″ bore. With this master cylinder there are three brake line ports (one for the front right, one for the front left, one for the rear).

Obviously you cannot easily interchange the two types (although we understand that there is a three-to-two line adapter kit available). However, either type should work just fine with the 11″ brake upgrade.



Installation of the new components is pretty straightforward; the brake line junction might be a fun one for you if the lines are rusted but otherwise it’s pretty easy. Once all is assembled, you’ll need to refill your master cylinder with the correct fluid and bleed the front brakes. When you’re all done, don’t forget that you’ll need to get an alignment ASAP.



One area of concern that people have mentioned seems to be low pedal feel and they usually blame it on the stock master cylinder. If you’ve converted to 11″ brakes and still believe the pedal feels low then it might just be that your stock master cylinder is just old and tired, and needs replaced. It seems like this brake upgrade, for some reason, will expose the flaws of the stock braking system rather easily.

If this is the case, you can definitely upgrade in the process. For the 1983-86 cast iron type, a 1984-86 Crown Victoria m/c works great, with its large 1-1/8″ bore. For the aluminum 1987-88 m/c you can use a 1994-95 Mustang type without ABS brakes.

Also, try adjusting your rear brakes after you complete the front brake upgrade. A little adjusting of the drums might just help.

1993 Mustang Cobra Brake Booster

If the brakes still don’t feel right, you can get a bigger brake booster. LMR is now selling a new 1994-95 Cobra brake booster that is the gold standard of Fox boosters. It may require elongating one of the stock mounting holes but otherwise fits fine and even clears the strut tower decently.

Also, you should consider stainless steel front brake lines; there are numerous aftermarket street-legal versions made for the Mustang that will work perfectly.

Whatever you do, DO NOT attempt to lengthen the pushrod going into the master cylinder! This can cause your brakes to totally lock up and you could possibly lose control of the vehicle. One of the above suggestions should solve your low pedal problem just fine.

4-to-5 Lug Brake Conversion

While’s there’s technically nothing wrong with the stock 4-lug bolt pattern on your Cougar, if you ever want to upgrade rims then you’re in for a shock: it’s getting more and more difficult to find new, aftermarket 4-lug spec wheels for our cars. Even some older factory 4-lug Ford rims are getting tough to hunt down. And pricing (with shipping) can be a deal-breaker sometimes. You may yearn for something that is a little more modern—more “normal”. Enter the 5-lug conversion.

There is a whole new world of possibilities for rims when you have a 5-lug pattern. For example, just about any 1994-2004 Mustang rim will bolt right up with no problem. Or if you’re going retro, a set of BBS 16″ spoked Mark VII rims look sweet. The choice is yours—if you’ve already found that perfect rim, but need to swap to 5-lug, then this is the section for you.

For our vehicles, Ford uses the 5 x 4.5″ bolt pattern on almost all of its late-model 5-lug rear drive vehicles. The only exceptions, ironically, are the 1989-97 T-Bird/Cougar and 1993-98 Mark VII, which use a very unusual FWD 5 x 4.25″ pattern (from the Taurus, Sable, Continental and Windstar). While Panther platform (Crown Vic/Grand Marquis/Town Car) wheels have the correct pattern, the offsets are too great to make work without a lot of reconfiguring.

Physically changing the front over to the 5-lug pattern can be rather simple (10″ rotor) or more complex (11″ rotor, 13″ rotor), depending on your preferences. The rear, however, is going to require axle work at the very least, along with the requisite brake work. This can be a daunting task for the uninitiated so if you’re a bit apprehensive, have a professional do the work for you.

Also, please keep in mind that there are many ways to achieve a full 5-lug conversion. There is no single “right” way to do it, simply because there are a lot of different parts from which to choose. We hope that this section helps demystify the situation and inform you of your choices so that you can make the best decision for your purposes.

Generally speaking, the front will likely need a spindle change along with the new 5-lug rotors. Out back, you will need to change the rear axle shafts at the very least. Going from drum to disc will entail a lot more work and parts. It’s possible to just swap in the entire 5-lug rear end to solve that issue.




Stock Rotors (10″)

Until recently there really wasn’t a pre-made bolt-on solution for 10″, 5-lug rotors. Not long ago we were contacted by Brian Portez of Complete Brake Service in Columbus, OH. Brian says that his company has 10″ 5-lug rotors for the Fox Cougar/Thunderbird (and 4-cylinder Mustang) in stock. This is about the only place that has come forward about these rotors and the only place we’ve ever heard that carries them. They’ll even ship the rotors anywhere. The price (around $60/each US) is very competitive. You can visit their website or you can call 1-800-581-2339 (locally 614-221-4888), and ask for Brian.

Jason from FL writes: “Just installed the 5-lug 10 inch rotors. Fit was perfect, quality seemed excellent. Price was good at $129.00 U.S. plus shipping. I got rotors, new inner and outer bearings, seals and dustcaps. Shipped to my door in 3 business days. Thumbs up from me!”




Fox Rotors (11″)


11-Inch 5-Lug Rotor

If you have already upgraded to the 11″ rotors then the only direct swap 11″ 5-lug front rotor will be from the Lincoln Mark VII (~10-49/64″). Keep in mind that most Mark VII’s had ABS brakes, which means that an exciter ring was part of the rotor hub. This increases the cost of the rotor; however, you should be able to find a Mark VII rotor for a car without ABS. Also, you will need at least a 15″ rim to clear the brakes. (If you haven’t upgraded to 11″ Fox brakes but are planning on doing so, see the information here). Also, you should know that with the dust cap on, the center caps of certain wheels may not fit properly over the Mark VII rotor (in particular, the popular factory Torque-Thrust style rim). The rims affected tend to have very small (under 2″) center caps. To resolve this, most people run without the dust caps and/or center caps. Just an FYI in case you were planning to run those rims.


SN95 Mustang Rotors (~11″)

Since the Fox 4/SN95 Mustangs use a modified Fox suspension up front, you can use that car’s braking system on your Cougar. What you have to understand is that it’s a little different than what’s on your car. In 1994 Ford opted to use the hub-type system on the front of the Mustang, meaning that the rotor does not have studs, but rather holes to slide over the hub that’s bolted to the spindle. It’s not that major of a difference but it does mean that you’re dealing with different parts than what you’re probably used to. However, you will happy with the relative ease of installation and assembly, and the comfort of knowing that you have a more modern system on your car.

The biggest advancement with Fox 4/SN95 Mustangs is that they all have comparatively large rotors from the factory, roughly 11″ in diameter. Again, you will need at least 15″ rims to clear the braking components. You can use the following parts:

Spindles: Any 1994-2004 Mustang can provide the spindles. However, there is a difference between the two major styles. In relation to the standard Fox spindle, the 1994-95 Mustang spindle moves the ball joint 20mm forward, 27mm outward, and 1mm down. The wheel center moved 17mm forward, 23mm outward, but is the same height. The outer tie rod end is moved 20mm forward, 41 mm outward, and 4mm up. The second style is the 1996-2004 Mustang spindle, which compared to the earlier ’94-’95 spindle, has the lower ball joint moved 1mm rearward, 5mm inward, and 2mm down. The wheel center also moved 1mm rearward, but is the same width and height. The inner tie rod end is the same fore/aft and width, but moved down 28mm. This may all sound confusing, but in a nutshell, the 1996-2004 spindles lower the point where the tie rod attaches by about 1″, and also pushes the spindles out slightly. Essentially they’re meant for lowered cars. They are more conducive for performance driving (autocrossing, etc.) but will require slightly modified alignment settings, caster/camber plates, and a bump steer kit. They also have a revised casting that will allow for larger 13″ Cobra brakes later on, should you choose to do so. The 1994-95 spindles work perfectly well with stock caster/camber settings on a Fox Cougar/Thunderbird at stock ride height. Again: non-lowered car, 1994-95 spindles. Lowered car, 1996-2004 spindles. Do not mix 1994-95 and 1996-2004 spindles on the same car! You must get a matching pair.

Calipers: Any 1994-95 or 1996-2004 Mustang can provide the calipers, so long as they match the rotor size (see “Rotors” below).

Brake Lines: It may be possible to reuse your front rubber brake lines, but if not, then 1994-2004 Mustang ones can be used.


Bump Steer Kit

Tie Rods: You will need to change at least your inner tie rods to SN95 (1994-2004 Mustang) specs. You can try to use SN95 outers first, but most people report having to change the inners as well. If you’re lowering or have already lowered the car, you should go with a good quality bump steer kit (shown above) in place of tie rods. Jeremy writes, “Fox inner/outer tie rods have SAE threads. SN95 inner/outer tie rods have Metric threads. If you go with SN95 brakes you must change both inner and outer.”

Ball Joints: You will need to change ball joints to SN95 specs. If you’re keeping the stock ride height, the stock SN95 pieces are fine. Otherwise we’d highly recommend Steeda’s X2 ball joints for lowered cars.

Hubs: This is a sealed unit that contains both inner and outer bearings, and all seals. Any 1994-2004 Mustang can provide the hubs; they’re all the same. New they are about $70 US each. Ford sells remanufactured units (check dealership for pricing).

Brackets: These hold the caliper to the spindle. The system is designed for easier brake size upgrades; for example, if you were to ever go from 11″ to 13″ Cobra rotors, the appropriate bracket change is also needed. Make sure your brackets match the calipers and rotors (see below). Bracket bolts (2 per side) are metric!

Pads: Again, these must match the caliper (see below).

Rotors: BE CAREFUL. With the “New Edge” styling of the Mustang in 1999, Ford also made suspension and braking changes with the Mustang across the board. The front rotors increased in size then, and the calipers went to a dual-piston design. Therefore, if you are using 1994-98 calipers then you must use 1994-98 rotors, pads and brackets. And if you’re going with 1999-2004 calipers then obviously you’ll need 1999-2004 rotors, pads and brackets. It is really your choice as to which years’ system to use, so long as you understand that everything must match. A lot of people are opting for the 1999-2004 braking system just to get the better calipers.


Mustang Cobra Upgrade (13″)


13" Cobra Brakes

If want to upgrade to a killer braking system, the Cobra 13″ disc brake conversion is a very popular choice and probably one of the most affordable in comparison. It’s basically the same brake setup as the 1995-2004 Cobras (and the Bullitt/Mach I). You will need at least 17″ rims to clear these brakes (5.75″ backspacing). Essentially the upgrade is just like the 11″ SN95 upgrade outlined above, with these exceptions:

Calipers: You actually have several choices. Ford opted to use the braking system designed by Australian manufacturer PBR on the Cobra and Bullitt. Therefore you can use the 1995-2004 Cobra caliper (black with white COBRA letters on the front) or the 2001 Bullitt caliper (red with a silver Pony on the front). Or, if you want to be different, you can use a 1988-96 C4 Corvette PBR caliper (silver and finned) made for 13″ rotors.

Brake Lines: It is highly recommended that you use Russell street-legal stainless steel brake lines. Factory Cobra lines were notorious for bad pedal feel.

Banjo Bolts: The PBR caliper uses a metric banjo bolt. If you cannot obtain these bolts from Ford then take a trip to the GM dealer and get them for a C4 Corvette (1988-96 vintage).

Brackets: 1995-2004 Cobra. Bracket bolts (2 per side) are metric!

Pads: All of the PBR 13″ calipers use the same pad so a Corvette pad fits the Cobra, and vice versa. Bad news is, they aren’t cheap. The ultimate in pads are NAPA Ceramix, which are very quiet and produce much less brake dust than any other pad out there, but cost around $150 US. Shop around for pads if price is a factor.


Rotors: DO NOT use pre-1999 factory Cobra rotors as they are notorious for warping prematurely. These faulty rotors were replaced in 1999 with much stronger Brembo 13″ units. You can get them new at the Ford dealer for roughly $100 each. You also have choices in the aftermarket, such as slotted or cross-drilled, from a variety of manufacturers.

M-2300-K Cobra Brake Kit

Ford Racing used to sell a complete upgrade kit (M-2300-K) which made life easier for this conversion (well, save for the price tag). Since the kit is now obsolete, you’ll have much better luck gathering the individual parts for the conversion.


Misc. Aftermarket Front Brake Upgrade

If none of the above appeals to you, you’ll probably want to check out manufacturers like Brembo, SSBC and Baer in this case. The good news is, anything that fits a 1979-2004 Mustang will work on your car. So that means multi-piston, exotic rotor systems can definitely be adapted to a Fox Cougar/T-Bird.




In back, things do get a bit trickier. What is true is that you must change the axle shafts to those with a 5-lug pattern. Then you must get the appropriate 5-lug brake drum (stock) or disc brake rotor (upgraded). Really, that’s it in a nutshell, although that’s really simplified. The reality is that there’s still quite a bit of work involved.


Axle Shafts

Now you can have your stock shafts machined for the 5-lug pattern, but as affordable and plentiful as new or used 5-lug axle shafts are these days, it makes more sense to search those out. Regardless of your model year 1983-88 and your rear end width, these axle shafts will directly swap into your Cougar’s rear axle:

  • 1994-98 Mustang-width axle shafts (29 15/16″, 7.5″ or 8.8″, non-ABS)
  • 1983-92 Ford Ranger pickup axle shafts (2 driver’s side, 29 1/8″)
  • 1986-97 Ford Aerostar minivan (2 passenger side, 29 1/8″).

All stock Ford passenger car rear ends of our era had 28-spline axle shafts. If you need to see more specific information concerning rear end widths, axle shafts, and brake configurations, or simply need photographic references, please see the thread posted here. You can also visit this site for a chart with measurements.

It’s also been brought to our attention that while the bearing location on the 1994-98 V6 Mustang axle shafts is basically correct, the location where the axle seal rides is .190″ larger in diameter, necessitating an alternative axle seal (Timken 3459S).




9″ Drum Brakes

Most Cougars from 1983-88 had the standard 9″ rear drum brakes, as denoted by the finned side profile. Now there were two types of drums: those used on 1983 through Nov. 1984 (mid-85), and those used from Nov. 1985 (mid-85) through 1988. The earlier drums had a large hat section bump out. We haven’t found any stock 5-lug drums with that larger hat section; if you have this type then you’ll probably have to get your drums machined with the 5-lug bolt pattern.

For mid-85 through 1988 owners, all you will need is new 9″ 5-lug drums from either a Ranger or Aerostar. You can leave your stock backing plate and old hardware on the rear end. All there is to it—no other mods necessary.


10″ Drum Brakes

The 10″ drum came standard on all 1988 Cougar XR7’s (8.8″ axle), and other 1988 Cougars (7.5″ axle). The side profile of a 10″ drum is totally smooth. Unfortunately we don’t know of a direct-swap 10″ 5-lug drum although it may be possible that Rangers had them as well. You can simply get your drums machined for the 5-lug pattern to solve the problem.

Bob found some 10″ drums that are very close, with minimal machining needed: “I found 10″ drums that fit the 29-1/8″ Ranger axles. The only modification is to machine 100/1000 out of the hub center hole. They are sold at NAPA, part # 440-1099. They are made for 1964-72 Mustang.”

It’s possible that there is a 10″ 5-lug drum out there waiting to be swapped in. If you do find that information, please contact us so that we can share that info with everyone here.




1987-88 Turbo Coupe 10″ Rear Discs

If you’ve already swapped in a Turbo Coupe rear with its stock 10″ disc brakes, it’s a little tricky to try to keep the stock vented rotors and just redrill them with the 5-lug pattern. Eric writes, “I had my stock TC vented rotors machined to accept the 5-lug pattern, and used 1994-98 Mustang axle shafts. But I found out that the center hole in the rotors were too small for the hub on the flange….so they had to be machined out. Then the flange on the axle would not allow the hub of the stock rotor to seat properly. So the shafts came back out and the flanges had to be machined down to a 45 degree bevel. Only then could I bolt everything back up. Yes, it was a royal pain and yes, it was expensive. The job got done, but it was a real trial to keep the stock TC rotors with 5-lug.”

While you could use a 1994-2004 Mustang rear braking system (see below) and install that, the rotors would be solid. That requires removal of the TC mounting plate for the caliper bracket. Since it’s tack-welded on, you’ll need to grind/hammer it off. All of the more modern Ford rear ends with disc brakes use a clamp-style hold down for the brackets, similar to a muffler clamp. Then you can install the rest of the SN95 components without a hitch. Again remember that you would be downgrading to solid discs.

If you want to keep vented discs, the ones found on the 1991-92 Mark VII (see below) should work just fine.

Or, you could do the ol’ Mustang conversion trick: use 1990 Mazda MPV (V6, 3.0) front rotors, and 1/8″ spacers. Place the spacers between the rotor hat and axle flange to put the rotor back into alignment with the stock Turbo Coupe caliper location.


1984-92 Mark VII Rear Discs

The Lincoln Mark VII usually had 4-wheel disc brakes but some had drums, so be careful when checking them out. The Mark VII, as with a lot of Lincoln components, had their own unique vented 10.5″ rear discs through 1990. This means you would need to use Mark VII rotors, calipers, pads, brackets and bolts. From what we understand it’s not simple to do the 1984-90 Mark VII rear disc swap. From 1991-92 the Mark VII had 10″ vented rear discs in 5-lug and those would be the ones to get. You could then reuse the other stock Turbo Coupe components.


1994-Up SN95 Mustang Rear Discs

If you don’t want to go through the hassle of machining the rotors for the 5-lug pattern, or if you just want to make everything match with your current rear end, then SN95 Mustangs can provide a very nice rear disc braking system for your car. The beauty of the system is that it uses Turbo Coupe-style parking brake cables, making installation easy on your car. The stock 1994-98 Mustangs had a ~10″ solid rear rotor with a small Varga caliper. In 1999 Ford bumped up the size to almost 11″. To get either system to work on your car you will need the calipers, rotors, brackets, bolts, backing plates and pads. Make sure that you get all the parts from the same year car—do not mix parts from a 1996 with a 2000, in other words. See above for the appropriate axle shafts needed.


1995-Up 11.65″ Mustang Cobra Rear Discs

The Cobras, Bullitts and Mach I’s are the only SN95 cars to use vented rear discs. You cannot use a Turbo Coupe/Varga style caliper with the Cobra rear disc; you must use an SN95 rear caliper at least, possibly Cobra-only. Also, you must use Cobra mounting brackets available at MPS. Everything else is similar to the Turbo Coupe/SN95 solid disc info as outlined above.



Finally, it might be easier or less costly in some cases to just swap in an entire 5-lug rear end. There is another section here that contains information on doing just that.

Aftermarket Hoods

Back when these cars were new, there were a few companies that made aftermarket fiberglass hoods for the Fox Cougar/Thunderbird, thanks to the aero Thunderbird’s popularity in drag racing. In the 1990s companies pretty much stopped making them altogether, as they focused on newer and more popular cars and trucks. But starting in the late 1990s, a resurgence came about in making quality fiberglass hoods for our cars. Whether you just want a different look, need a lightweight hood for racing, or need a taller hood for engine clearance, this is actually the best time ever to buy one.

Listed below is the most complete and comprehensive list of aftermarket hoods currently available for the 1983-88 Cougar/Thunderbird. If you happen to know of one that’s not listed here, please contact us so this information can be shared with everyone.

One note of caution: remember that with any aftermarket fiberglass hood, you will probably not be able to use your hood latch to pop the hood anymore. These hoods typically require hood pins of some type, whether a physical pin and lanyard, or a locking key style. You can find either type at Summit Racing or Jeg’s easily. You have to ask yourself whether you want to lose your car’s functionality in the hood latch department before buying one of these hoods. If you can live with that fact, read on.

NOTE: Please visit manufacturers’ websites for current pricing and shipping rates.

US Body HoodUS Body Hood

The hood shown here is from US Body Source in FL. It’s a 3″ Dominator cowl hood with a fully finished liner (underside), completed in gelcoat and primed for painting. The cowl is not functional; the liner assures that it’s completely blocked off underneath. In other words, it’s not a functional cowl hood where engine heat can escape in the cowl area. But that shouldn’t stop you from considering it if you want the look (and besides, you could always customize it to your needs if necessary). The workmanship is excellent and this is a great choice for a show vehicle. There is minor trimming necessary around the perimeter (removal of a 1″ lip) and near the windshield, and it is recommended that you block sand the top to get some of the waves out. We did find minor pinholes in the gelcoat that needed filled in; not really an issue since all hoods have this. Otherwise, that was the extent of the labor involved.

US Body HoodUS Body Hood

US Body also makes this hood in a lightweight racing version, and makes stock-type hoods in bolt-on and pin-on versions. Part numbers are as follows:

1983-88 Stock Hood (top left), p/n FTBH-2
1983-88 Dominator Hood 3″, p/n TTBH-83

1983-88 Stock Hood, p/n TBH-1
1983-88 Dominator Hood 3″, p/n TBH-7C
1983-88 10″ Torpedo Hood (bottom left), p/n TBH-92

Champion Fiberglass HoodThis 3″ fiberglass cowl hood is from Champion Hoods and Products in OH, which the company says is a bolt-on hood utilizing OEM hinges, latch and hardware, and features a partially finished underside liner.

Crites Hood

This is one of the wildest hoods we’ve seen. It’s a creation of Crites Performance Parts from OH, which specializes in replacement and aftermarket parts for older Ford vehicles. This hood is listed as a ram-air style hood.

VFN Hood

This 5″ hood comes from VFN Fiberglass in IL, and the race version is even extended. Options are below:

  • Stock Flat Pin-On Hood
  • Stock Flat Bolt-On Hood
  • 5″ Extended Lift-Off Hood
  • 5″ Pin-On Hood (Not Extended)
  • 5″ Bolt-On Hood (Not Extended)

Hairy Glass Door

Hairy Glass from FL has been around for many years, and they still produce fiberglass parts for our cars. However, they’re mostly for drag cars and not practical for everyday use. Their selection is mostly for Thunderbirds but they have interchangeable Cougar parts available in fiberglass, including doors and hoods.

Showcars Body Parts

Showcars Bodyparts in Ontario, Canada also features fiberglass hoods and body parts, mostly for drag cars. They also carry stock steel body panels. Check the listings for your needs.


If you can’t afford a fiberglass hood, or if you prefer more stock-looking hoods, you do have some alternatives:

Turbo Coupe Hood

Turbo Coupe Hood

Most popular is a 1987-88 Thunderbird Turbo Coupe hood, which bolts right up to your Cougar. Obviously the scoops are no longer functional on a V6 or V8 car, and in fact should be capped to prevent water from leaking onto your distributor. Also, on 5.0L V8 cars the a/c bracket must be shaved down so that the driver’s scoop will clear. There may be minor clearance issues with other engines but nothing extremely difficult to deal with. With the availability of these hoods, and the comfort of knowing that it’s a factory Ford part, this is a very tempting proposition. Pricing is very erratic, however, so shop wisely.

Mustang Hood Scoop

Another solution would be to use an older Fox Mustang factory hood scoop. These were found on 1979-82 Mustangs and the lines are nearly perfect for the fitment on our hood. We have seen people put this scoop on facing forward or backward, and either looks pretty good. It does bolt on, so this requires drilling holes in your hood, but it will give a factory-type look that’s stunningly easy to achieve.

Along those same lines, you can always graft a different aftermarket hood scoop onto your stock hood. Some are fiberglass, some are plastic. Also, some bolt on, and some stick on. Really it’s up to you, your budget, and your willingness to drill holes in a perfectly good hood.

Custom Grilles

While there’s nothing wrong with the stock grille on your Fox Cougar, you may feel the urge to just do something different or custom with it. These are some good tips and suggestions if you want to make your grille look a little different from the stock style.



In the late 1970’s and early 1980’s a big chrome square grille was all the rage. When the aero Cougar came along in 1983, the grille took the form of a “rounded square”, if you will. While the overall shape and proportion definitely fits the car well, the copious amount of chrome slapped onto the grille is a bit incongruous with the rest of the front end. What to do? Well, a little paint goes a long way with helping your grille fit into the car’s overall scheme better.

1984 Cougar Custom Grille

This is a 1984’s waterfall grille after a little painting. The outer surround and the inner main vertical bars were body color. The inside waterfall sections were done in a flat black. Notice that the MERCURY emblem was left off. This perfectly mates your grille to the body, and from a distance the effect is amazing.

1986 Cougar Custom Grille

Here is roughly the same idea on the 1985-86 grille. In this phase just the outer part was painted body color. The chrome horizontal bars, vertical bar, and inner ring were left alone. The butcher block inside is also left stock.

1986 Cougar Custom Grille

The same grille, only with the butcher block areas painted gloss black. Note how the grille perfectly compliments the blackout headlight covers.


The classic Mercury waterfall grille fits this car perfectly. From the factory the vertical slats were painted a charcoal color on LS models and 1987 XR7’s, while the 1988 XR7’s had body-colored slats. A thin chrome surround is all that’s needed to let you know that this is a front end that perfectly suggests the Euro look without forgetting its classy American roots. It’s almost a shame to do anything with the grille, and really it’s not as flexible to modify as a 1983-86 grille. Still, if you want to be different, you’ve got at least one option (aside from painting the grille body color).

1988 Cougar Custom Grille

This viewer used aluminum diamond mesh that’s popular with import cars, and simply used paper clips to attach it to the stock grille. A very cool, very simple mod that anyone can do.


Grille Preparation & Painting

These grilles were either all metal, or ABS plastic with a chrome coating (simply tap your grille to figure out what you have). With either kind you will have to slightly sandblast the surface. The key is to simply knock down the shine of the chrome so that the grille looks like a dull metal when you’re finished. No shiny spots can remain. This is now a perfect surface for the paint. If you want to primer it first, go ahead but apply lighter coats. The paint can then be applied. Although it may not seem that this is a durable solution at first, in reality it works great. If you or anyone you know cannot do this, ask a body shop to blast your grille. Sometimes they can even use beads instead of sand to blast; this is a great alternative as it won’t damage the surface.

There is a chrome stripper exists that will remove this chrome plating without harming the plastic. It’s available to body shops and is really expensive. Check around to see if any shops in your area offer this service, because that would save you a lot of hassle.

Once the surface is roughed up a bit, be sure to sand over the surface with a Scotch-brite pad at the very least. A self-etching primer is also recommended for a good, solid base. Then you can paint the grille what ever colors you wish, with the usual rules about proper ventilation applying here as well (see our disclaimer for more details).

Finally, top coat with a good clearcoat, wait the proper drying time, and reinstall.

If you done this to your Cat, we’d love to see your photos! Feel free to contact us.

Tempo/Topaz Outside Mirror Conversion

Tired of dealing with chrome that fades and wrinkles and peels off your Cougar’s outside mirrors? Or are you looking for a full custom mirror look? Well, we’ve got a great solution for you, using parts that Ford had already manufactured.

These flush-mount mirrors are from a 1980’s-early 1990’s two-door Ford Tempo/ Mercury Topaz. They feature a two-piece housing, lighter weight, paintable plastic, flush mounting, and are easier to clean and repair. Surprisingly, very few modifications have to be made to get them to fit onto the door of a Cougar or Thunderbird. The aluminum window trim near the stock mirror needs to be cut back (you can guess very easily at this). One of the three mounting holes needs to be enlarged a bit. And that’s it—the wiring harness will plug right in, and when you tighten the mirror down on the inside, it fits absolutely flush on the outside. You may also want to drill a hole underneath and toward the front of the outer housing so that when you wash the car, water will drain out of the hole instead of waiting to fly out at 40 mph. Plus, if you ever break a mirror or fry a mirror motor, it’s much easier to get to the mechanism with this two-piece setup than with the stock mirrors.

Just for your information, the Tempo mirror trick works really well on 1983-86 cars, but for some reason it’s not as smooth of a job on 1987-88 cars. While it can be done, it’s much more of a chore to do.

The look is totally custom, fitting in very well with our door, and all using stock Ford parts. When searching for these mirrors, look for 2-door Tempos and Topazes, because some of the later 4-door models had their own unique mirror that won’t work on our cars. By the way, if you’ve been contemplating using a different car’s mirrors, a viewer has used Taurus/Sable mirrors on his Thunderbird but said it was more trouble than it was worth. The Tempo/Topaz mirrors are easier to find and install.

For an in-depth instruction manual on doing the Tempo/Topaz mirror conversion, download the PDF file here.

Ground Effects Kits

Probably the number one inquiry that we receive involves finding a ground effects kit for a Cougar. And with good reason: it’s the most brash, in-your-face way to separate your Cat from everyone else’s. But before you consider doing such a radical mod to your car, you must know the facts.

Ground effects are also known as a “spoiler kit”, “body kit” or “air dam kit”. At one point, ground effects kits for our cars got so popular that auto dealerships offered kits on new Cougars and Thunderbirds as a way to pad their profit margins. This is how the misperception started that there were “factory” ground effects kits. In reality, factory kits never existed; they were simply aftermarket kits that were sold to customers by the dealerships.

With the passage of time the number of companies that still produce ground effects kits for the Cougar/Thunderbird has dwindled to pretty much zero. Companies that used to build kits for our cars (such as A&A, Kamei, Erebuni and Pacifica) have long since discontinued them.

Trying to find these kits used is very difficult; however, they do (very) rarely show up on eBay. Some people have had luck with finding kits at swap meets or at salvage yards. Really, at this point in time, those are your only options.

No other vehicles’ ground effects fit our cars directly. Any other kit would require serious modifications and bodywork. That would include 1987-93 Mustang kits, as well as those for 1987-97 Cougars/Thunderbirds.

Using a 1983-86 kit on a 1987-88 car, or vice versa, also won’t work without modification. The dimensional differences, and the use of totally different bumpers, prevent you from doing this successfully. We’ve seen attempts to do this and the results are less than professional.

With that being said, the information below is the most current, up-to-date information about ground effects kits for the 1983-88 Cougar/Thunderbird that you will find anywhere. It will change as information is obtained, but for now it is extremely accurate.



Xenon Ground Effects

Xenon Ground Effects

A long-time manufacturer of ground effects kits for the 1983-86 cars was Xenon, a division of American Best Car Parts. They are still in the restyling business with domestic and import cars, and with trucks as well. This company also recently bought GTS, the maker of headlight covers. Xenon does not carry the 1983-86 Cougar/Thunderbird kit in their catalog anymore. While it’s entirely possible that they have the molds to make more of those kits, the demand is probably not there from their point of view. Pricing for a Xenon kit was in the neighborhood of $550-600 US.

Below is some legacy information concerning the Xenon kit:

The urethane Xenon kit is 4-piece (front air dam, rear valance, pair of side skirts). Fitment of the front and rear pieces are very good. However, the side skirts leave a little to be desired. They require you to attach them inside the door seam, instead of just below on the rocker panel itself. As a consequence, the urethane that slips under the doors is very, very thin and has a tendency to wrinkle and ripple. A custom aluminum piece to slip over this section will help keep them from rippling.

The kit was designed around the Turbo Coupe/XR7 bumper cover with foglight cutouts. It is possible to use this kit on cars with the stock bumper covers in front, but you will need to cut out for the foglight provisions in the air dam. For cars that have the turbo cover, the air dam slips right on and mates up to the stock lower dam perfectly.

Part numbers for Xenon’s kit were as follows:

  • 8131 Air Dam w/Fog Light Cut Outs
  • 8135 Right Side Skirt
  • 8134 Left Side Skirt
  • 8132 Rear Valance
  • 3003 Rectangular Light Kit/3.25″x6″/Fog Pattern/Clear Lens
  • 8000 Complete Kit (8131,8135,8134,8132)



GST Ground Effects

The boldest kit seen to date was offered by GST. The fiberglass kit included the front air dam, side skirts, rear valance, trunklid spoiler and a pair of Monza exhaust tips that exit the rear valance. GST sold the kit for a whopping $950 US. GST has gone out of business and sold some of their molds to private individuals. While we do know that the Cougar/Thunderbird molds were purchased by an individual, we don’t know if any kits will be produced in the future.

Part numbers for GST’s kit were as follows:

  • 13000 Cougar Kit (front valance, rear valance, 2 side skirts, 2 exhaust tips, all hardware and instructions for install)
  • 18901 Optional Rear Spoiler
  • 47801 Optional Rear Spoiler
  • 54448 Light Kit


McK Ground Effects

McK Ground Effects
This ABS plastic kit was available from Kobel. In the early 2000s McK Plastics bought the Kobel brand and used the Kobel molds. The kits listed for $479 US. Kobel/McK no longer produce this kit.


McK Ground Effects

McK Ground Effects

This is the Kobel/McK Cougar front air dam. The rest of the kit was identical to the Thunderbird’s above. Thanks to Scott for the photos.

LED Lighting Conversion

As much as you may otherwise believe, I’m just an average schlub like you. I have a regular job with regular pay, most of the time I have weekends off, and if there’s any spare time during the week I try to get into the garage and work on the cars. And when you have more than one car that you’re trying to keep roadworthy, of course, that gets really tricky…and expensive. But that’s how I roll.

So I set off in the winter of 2018 with the hopes that I could actually accomplish something great on at least one of the cars. The goal: convert an entire car over to modern LED lighting and make it look as stock as possible. Every single bulb. As it turns out, not only was the mission accomplished but I was able to convert BOTH cars in the same timeframe. It’s not often you can say that, right?




As we all know, our cars were created in the golden age of the incandescent 12v automotive bulb. They were dutifully used for many decades without much of a real improvement, save for maybe halogens. They gave off a yellowish light, they burned out after some time, and they generated heat. Those were all givens. But probably the most important, yet least thought-about, element of the incandescent bulb is that it gave off a consistent light pattern from all angles. You and I never really gave it a second thought, but all of our light housings and surrounding reflector areas were designed around this basic characteristic.

So when you start messing around with other types of bulbs such as LEDs, you begin to discover rather quickly that not all bulbs are created equal. And not all bulbs will mimic that omnidirectional light pattern (I’ve got bags full of unusable LED bulbs to attest to that).

Therefore my goal—and yours—is to find a bulb that mimics the stock bulb but in an LED pattern, and is also dimmable when needed.

Also, I must say that money was no object in my case. Whatever it took to get the job done, I was willing to pay for it. Just like any other trial-and-error automotive experiment, that means I have a few hundred US dollars’ worth of bulbs I’ll never use. So be it. I took one for the team so you don’t have to.



I found that converting the smaller bulbs is the easiest. Why? Well, LED bulbs that aren’t pulling a lot of power will generally not need an inline resistor. They’re just literally plug and play.

The most common bulb on our cars is the 194 (or 168, similarly) so that’s where I started. And the first place to get that new bulb would be the front side marker on my ’84. I’d know how well a bulb worked in that location because it would easily show uneven lighting. Plus, I could look at the car from the front and see both lights…if something was off a bit, I’d surely know it.

So off to eBay I went. There are lots and lots of different types, light ranges, and configurations out there. I quickly learned that the clustered, unidirectional bulbs aren’t worth squat for our cars. They make a single bright spot and that’s it. Next, I tried a round, domed bulb that looks similar to the incandescent bulb it’s replacing. Close, but no cigar…the light was still going in more or less one direction. At least they were inexpensive at under US $1 each.

At this point I was so disappointed with the early test bulbs that I decided to just stop looking for the time being. Multiple eBay and Amazon searches weren’t yielding any promising leads, and more of the same old bulbs that I’d just purchased were the only options, it seemed.

Then one day I was in a US national parts chain store and saw some name-brand LEDs hanging from the shelves. They looked interesting but I wasn’t sure. There was a tester display for them that seemed to work impressively well. However, I was giving a hard stare at the ~US $9 price tag. If the bulb worked, it was not going to be cheap to upgrade the whole car. But I was in this all the way, no turning back now.

The younger salesperson working at the store told me he used these same bulbs on his truck. We went outside and he showed me the bulbs in action for his license plate lamps. Even in the late afternoon sunlight, they seemed pretty strong and bright. So I bought one to try out.

When I got home, I was shocked at the evenness of the light. THIS is what I had been searching for!


Sylvania LED Bulb

The winner: Sylvania/Philips. They currently have two different product lines and I honestly can’t tell you what’s different about them. All I know is, the more basic bulb in the white packaging is more common in whichever stores you frequent. So that’s what I went with. These are the 6000K bulbs, by the way, also known as cool white.

It was at this point that some of the information I’d read about LED bulbs turned out to be true. If you’re putting an LED bulb into a colored housing, the bulb should also be that color. So in an amber housing you’d want an amber bulb, red bulb in a red housing, and white anywhere else. This ended up being true for almost every situation. Otherwise the colors will be off, and not in a good way. (Purple taillights tend to attract unwanted law enforcement attention, if you know what I’m sayin’).

LED Bulb ConversionLeft to right: stock bulb, no, no, OH yes.


Also, it is true that LEDs tend to work only one way in the socket. If you install one and try the light, and it doesn’t work, flip the bulb around the other way and it should. That’s because it is a diode, after all. That makes it VERY important that you try all the new bulbs out before you start reassembling.

LED Bulb Conversion

Later on I swapped out the white LED for the amber version in the front housing, and it is definitely better. It’s very hard to tell that there’s an LED bulb in there, almost impossible in fact. That made me very happy, as it foreshadowed the rest of the bulb replacement process.

LED Bulb Conversion

At this point, the front side markers, the rear taillight markers, and the license plate bulbs were all replaced. That was as far as I could go on the outside with 194 bulbs.

Total so far: ~US $60.



One of the most annoying issues with the 1983-84 dash is the lack of good lighting at night. It’s never been that good, to be honest, and over time the bulbs will start fading and dust will collect inside the cluster housing. This is one area where we all can use some help. So into the dashboard I tore.

For the 1983-84 cluster there are only 4 main 194 illumination bulbs. After swapping them out, I made the garage dark and hit the headlamp switch…what a HUGE difference in lighting quality. Best of all: they are dimmable! Now you’re not going to get the same kind of dimming as incandescent here. It will go from super bright down to bright-ish, but not dim like before. Just so you’re aware. But for my tastes, these were perfect as I always had the dash lighting cranked up anyway.

LED Bulb ConversionUpgraded dash lighting makes a world of difference.


Full disclosure: to save a little money I did not change out the warning lamp bulbs nor the turn signal indicator bulbs. Those will get replaced with LEDs when and if needed.

LED Bulb Conversion

Eventually I also did swap out the clock bulb, the heater panel bulb (fun!), and even the bulb inside the lighter. What, you didn’t know there was a bulb in there?

Next, I tackled the console with the ashtray bulb. This marked the end of the interior 194 bulbs…the rest would be different types that I hadn’t found quite yet.

Total so far: ~US $140. (Ouch.)



So far, the most straightforward bulbs had been replaced and I was about a third of the way done. It felt good to accomplish this but I knew there was a lot more work ahead, and also some more research needed.

I wanted to work on the exterior lighting once more, and not knowing if the Sylvania/Philips bulbs were going to work, I decided to try some cheaper omnidirectional white 1156 LED bulbs that I found on eBay. Those are used for the backup lamps, and the trunk and hood lamps. They did not disappoint: lighting was even and very bright. Another few off the list! (In hindsight, the Sylvania/Philips bulbs would also be just fine in these locations).

So out back, all that was left was the brake/turn signal bulbs, and in front, the turn signal/marker bulbs and headlamps. I’d get to those later.

LED Bulb Conversion

Back inside the car, I went on to replace the courtesy lights with the same 1156-style bulbs.

LED Bulb Conversion

Then it was time to tackle the dome light. Did you know that there were two different styles of map dome lights in our cars? It depended on the model year, but the earlier cars had the older, fuse-style bulb while later ones had the plug-in style base. For my car, the 1156-style LED bulbs worked awesome in the map lights but I didn’t find the correct fuse-style LED bulb for the dome light itself at the parts store. In the end, I bought 4 different ones off eBay and used the brightest one. Can’t tell you where it was from. I don’t know if Sylvania/Philips has an equivalent. But I can tell you that WOW what a difference in interior lighting now. When the door is opened, there is real, bright, usable light. It’s probably enhanced a bit by the blue interior color too, but it’s still quite impressive.

The console bulb was a little tricky, as Sylvania/Philips doesn’t offer that size. Again I went to eBay and was able to find one that worked. It’s not ideal, as the bulb isn’t frosted so it’s more of a uni-directional light, but it’s pretty bright and makes the console usable again.

That leaves the glove box lamp. And boy, did that ever kick me in the backside. After struggling with a lot of popped fuses over a few weeks’ worth of fiddling, it turns out that the stock glove box lamp holder does NOT like LED bulbs. At all. However, with the help from the message board, I was able to “fool” a bulb into working by covering up one side of the contacts. That was actually the very last bulb to get converted on the whole car.

Total so far: ~US $180. (Starting to hurt).



At this point the car was about 70% converted and I was pretty happy with the results. But the hardest part was still ahead: getting the brake lights and turn signals to work with LEDs, and without killing anything in the process.


LED Electronic Flasher

I had heard some things about this whole deal, and in the end they turned out to be mostly true. In order for LED turn signals to function like an incandescent setup, you will need an electronic flasher, and preferably one made for LED bulbs. The new flasher will have a ground wire coming from it, and that wire will absolutely need to be grounded before the flashing can occur with LEDs. Fortunately there are a few spare screws hanging around the fuse panel area that go right into direct metal. That’s where I put the ground. The flasher was US $7 from eBay and it’s round, just like stock. I know there are some square ones that could work with wire extensions but don’t do that unless you have to. You will not need to change the 4-way flasher, by the way.

(Interestingly enough, with the new LED flasher installed, I tried the incandescent bulbs first and they still worked fine. Good to know in case you ever need to change them back or change out a dead bulb when you’re on the road, or if you’re mixing LED and incandescent bulbs in your particular setup.)

Also, I’d heard that taillight bulbs were the trickiest. Most people want you to believe that the “tower” bulbs are what you want. But I wasn’t so sure because the ones I tried were rather unimpressive, and not very bright to boot, despite their high brightness ratings. I decided to try the Sylvania/Philips bulbs because so far, they were doing a great job at everything else.

What turned out to be semi-not true is the need for any inline resistors. In general, older cars like ours don’t need them; however, in the case of light bleed—where even with the lights off there’s still a faint residual luminance from the bulbs—then resistors might be needed. More on this below.

So I got my amber 1157 LEDs for the front turn signals and tried them…very nice, and they flashed just like usual. Again, I got the Sylvania/Philips bulbs in the white package. The ZEVO ones are a little weird looking and I didn’t really care to try them.

LED Bulb Conversion

With the front of the car mostly done, it was time for the rear brake/turn signal bulbs. I was sweating on those, because of the all-or-nothing move…plus, when you’re dropping US $60 on the bulbs, you expect them to work like you hope they will. Well, they turned out pretty awesome. The red Sylvania/Philips 1157 LEDs are very bright. I am pretty happy with them, and although I wish there was more of a difference between the dimmer and brighter flashing, I’m not about to go looking for different ones right now. They’re doing their job just fine.

The car, at this point, is about 95% done. All that’s need now is LED headlamps. But do those even exist?

Total so far: ~US $267. (Holy moley).



It turns out that, yes, LED headlamps do exist. This is the standard 4×6 sealed beam style, and if you go on eBay or Amazon, you’ll find an absolute boatload of them for sale. But are they any good? I’ve seen different ones in real life and looking at them from outside the car, they sure seem pretty bright. But you never know until you actually drive the car at night to figure out if it’s going to work.

Most of these headlamps look okay. Some are gimmicky. A good majority of them don’t have a good warranty, which means they’ll likely die prematurely, which means I wasted money. Some are completely sealed up…again, that’s fine but I don’t want something that gets thrown away.

My goal here was to find stock-looking housings with replaceable LED bulbs. Sounds easy, right? Then you try to find them. Not so fun. I mean, I could buy stock-looking H4-style housings and put LED bulbs in them. But then you have H4 wiring to deal with. I’m too impatient for that sort of thing. I want a well thought-out solution.


LED Bulb ConversionWhich one is stock, and which one is LED?

Fortunately I found them after digging for weeks. The winners are from Octane Lighting. It’s nearly impossible to tell these H4-style LED housings from stock. And the light output…to say it’s like daylight is pretty accurate. The bulbs are pre-wired for older cars so not only can they get replaced if necessary, they won’t require fiddling around with the wire harness or require an adapter harness. The warranty is pretty good, too.

A really unique feature of the bulbs are the built-in cooling fans. Each bulb has one, and when you turn the lights on they whir and whir like a 1996 Windows laptop. Seriously, I have no idea if they even could get that hot, but it’s nice to know they’ve got some assistance in any case.

One thing I discovered is that these particular LED headlamps put out the same general side-to-side pattern as the stock headlights, but the they tend to aim pretty high. You have to adjust them almost all the way down to get them correct enough. I’m still fiddling with the adjustments but at least oncoming cars aren’t blinded anymore.

LED Bulb ConversionLED on the left, and the rest are stock.

LED headlights are just awesome and make a huge difference in visibility. These ended up being around US $40 each, which isn’t cheap but have you priced regular sealed beams lately? They’re approaching US $15 each now and you can’t even replace bulbs in those. These ended up being a relative bargain in that respect, and for me it was the best decision.

If you are switching to LED headlamps and try different ones, please let us know about your experience. There is no “right” or “wrong” here, just whatever works for your preferences and your budget.




So now the ’84 has a really modern lighting feel, and such usable light that I wonder how I’d put up with the old lighting for so long. It turns out that technology had to catch up to our lifestyles first, and in doing so it got pretty reliable in the process.

That being said, what I really wish is that Sylvania/Philips or some other major brand-name manufacturer would start marketing a “nostalgia” line of bulbs that are in the 4000K light range. That way, we could have modern LED bulbs but in the same yellower color range as stock (3500-4000K), with none of the disadvantages. I mean, sure, you can find 4000K bulbs on eBay but will they put out a good light pattern? Will they start flashing after awhile, as some people report? Will they last for a long time? Do they even have a warranty? That’s why a major brand name needs to step in. Marketing that to people with old muscle cars would be an easy task. Even putting together conversion kits could be a thing. It sure beats piecing it together like I had to do.

Alas, I don’t know if there’s much of a market for some of the odd bulbs in our cars, at least for a good name brand. I really, really wanted to go all Sylvania/Philips with this conversion but it just wasn’t possible.

Amazingly, most of the bulbs marked as 6000K actually were in that range. Sure, a few of the eBay ones were bluer, but it didn’t really matter in the overall scheme of things. Getting a consistent color range across an entire car is now mostly possible…as long as you like bluish white.

There is a slight amount of light bleed in the taillights when the headlights are off and the car is running. It’s not annoying and actually photographs way worse than it looks in real life. And it doesn’t affect performance as far as I can tell. I’ve been told that the taillight bulbs might need inline resistors to resolve the issue, and that makes perfect sense to me. When time allows I will definitely experiment with them and report back here.

Thus far, I’ve notice no interference with the radio when the lights are on (another warning from teh intarwebs) although I haven’t really put it to the test that much. Also, none of the bulbs flicker or have had any issues staying lit for extended periods. That’s undoubtedly because of quality control by Sylvania/Philips. I suspect if any bulbs start going, they’re going to be the eBay-bought ones.

Lastly, Octane Lighting doesn’t sell any 5000K headlamp bulbs. Maybe one day they will. Or maybe someone else will make them in H4-style, and I can just swap them out. But until then I’ll be happy with these.


UPDATE 1: Recently, the car site Jalopnik ran an article about putting quality LED bulbs in your car, entitled Why You May Want To Buy $10 LED Bulbs Even If $3 Ones Are Brighter. It basically reaffirms what I discovered in my own conversion and is well worth the short read.



If you’ve read the article thus far, there’s no real need to rehash things for the ’86 as the bulbs are almost all the same on that car as well. Well, it doesn’t have a dome light. But there are door courtesy lights and the rear reading lights that got turned into entry lights, so I had to replace those.

LED Bulb ConversionA dramatic difference in visibility.

Also, the convertible has AutoMeter aftermarket gauges and I have to say that I’ve always hate, hate, HATED the stock incandescent bulbs in them. They made the gauges practically unusable for me. Well, after some Sylvania/Philips 194 LEDs, I’m happy to say that they are now just awesome. Very bright, details really pop out, and they’re much easier to see at a glance. Couldn’t be more pleased. I went ahead and replaced the turn signal, high beam, and other indicators with LEDs in this car, by the way.

One of my main areas of concern with the convertible was how the LEDs were going to affect the sequential turn signal kit. I’ve been using the Cougars Unlimited kit since 1997 and it has never failed me. But I know LEDs can throw things into chaos if not done properly. Fortunately, Vic the owner is still around and a few quick emails to him got me on the right track. Instead of replacing my main sequential electronic unit, I just had to buy an add-on box to take care of the resistors, and a custom-built electronic flasher unit. These were both not cheap but they were still cheaper than a completely new full LED sequential box, and they were both plug and play. Couldn’t have been simpler. Again I used the red Sylvania/Philips 1157 bulbs for the taillights.

Here is a view of the front turn signals, along with the cornering lamps:

So now, as the French say, the piece of resistance: the headlights.

To say I wanted a major cool factor to them would be an understatement. And I got them. Again from Octane Lighting, behold:

LED Bulb Conversion
LED Bulb Conversion
The halos are LED and are nearly identical to the style used on OEM vehicles today, meaning they’re high quality with consistent light flow and no cold spots. You can wire them in however you want, but I just put them on a switch. Some people like to use them for daytime running lamps and that’s fine also. I went with the 6K white halos, but Octane has all kinds of different colors if you so wish. (It would be cool to have amber ones for turn signals, though. Just saying).

The bulbs themselves are similar to the ones in the ’84. These H4 housings are diamond cut with clear outer lenses and a chrome bulb cap. They look awesome in the daytime as well as at night. These bulbs have similar cooling fans along with braided straps on the back to further help with heat dissipation. There’s kind of a lot going on behind the scenes, meaning between the header panel and radiator core support, as this kit has a lot of wiring and the braided straps and the inline resistor boxes. I was able to zip-tie them up out of the way for the most part.

Going off-script, I treated myself to a new LED clear/smoked third brake light for the trunklid, from a Chevy Blazer. Also got a new “hot rod”-style LED light for under the hood.

I actually worked on both cars simultaneously for the LED conversion. It didn’t cost any less to do the convertible either…in fact it was more, because the headlights were more expensive. For the convertible I’d venture to say the overall total spent was around US $550.

So…two cars, nearly US $1000 spent on things I really did not need to have. In the end, was it worth it?


Every penny.*

* Overall, I suppose that had I been pinching pennies, I could have likely gotten a majority of the bulbs cheaper on eBay or Amazon. They might have been okay, might have been in the correct color range, might last as long as these. There were a lot of unknowns going that way. You may or may not have a similar experience.



Hugh sent us these photos of his ’83 converted over to LED headlamps, the common variety that’s found on eBay:

LED Bulb Conversion
LED Bulb Conversion
LED Bulb Conversion

Hugh said that last photo was with the headlight covers on…that’s how bright they are!

We’d like to hear from you if you’ve also done an LED upgrade—let us know what you used, where you got the bulbs, how you like them, etc. and we’ll be happy to share your experience on this page. We encourage you to send photos as well, even though we know they don’t always photograph correctly. That’s okay, we’d just like a visual representation of your work.

Headlamp/Side Marker Modification

There’s one place on these cars that can always use a custom touch, and that’s in the area of lighting, particularly with the headlamps. The 1983-86 models have the standard 4×6 low and high beam sealed units that had been used for many years prior. One nice thing about that standard is how the lighting pattern was consistent across vehicles. While that’s great, there’s always room for modernization and improvement. The aero Fox Cougars saw a dramatic change in headlight design, beginning with the 1987 refreshening, with the new flush headlamp system and replaceable bulb. While a little more limited in upgrading, there’s still something that can be done if you want to make your Cat stand out at night.




Sylvania Silverstar H4651

Before going into any kind of wild/exotic headlamp setup, if all you’re looking for is a brighter and whiter light then look no further than the Sylvania Silverstar headlamp. It is a quality name brand and does deliver on its promise: the light is whiter, a bit stronger, and plays nicely with the System Sentry/lamp out system for those cars equipped with it. That’s because these are still halogen lamps. They are really close to stock appearing and we can attest that they look great. Don’t expect a miracle, but do expect a better light experience.

H4 Headlamp

The H4 conversion is the next step up from stock headlamps. The H4 headlight is relatively new to North America, although they have been available in Europe since the 1980’s. The idea is that they combine the size and shape of traditional 4″x6″ sealed beam headlamps, only with a replaceable bulb. Standard halogen bulbs are available, as well as hyper-white and xenon-imitation bulbs, and even full bi-xenon HID bulbs with conversion kit.

Unlike sealed beams, the H4 lamp will continue to function even if the lens is cracked or shattered because there is no high-pressure gas inside. But the real boon to H4’s is their light pattern: it works almost like a fog lamp, with excellent side-to-side lighting and the virtual elimination of a bright spot for the low beams. This is truly a blessing for those that want to upgrade to something more modern. Some versions are DOT street legal, while some are intended for off-road use only, so be sure to check first. Legality with H4’s is a delicate situation.

H4 Wiring Harness

A few things to note about H4’s: they work off a totally different setup as far as wiring configurations. Fortunately, most H4 kits will come with a minimal conversion harness that plugs right into your own stock harness, so be sure that you get this with yours. Better yet, if you can, buy a separate harness like the one shown here. It’s the ultimate in wiring security because it lets you run higher wattage bulbs (don’t even try it with stock wiring!) and it also pulls its power directly from the battery, ensuring a full 12v at each lamp. As far as the bulbs, the standard 60/55w bulb will probably be too dim. The 100/80w are good, or there’s even a 130/90w bulb available.

H4 Wiring Illustration

This illustration shows the wiring changes needed to accomodate the H4’s bulb configuration. Since the blades are in different positions vs. the stock setup, you will need to make sure that everything is wired for the H4’s. And if you are going to use H4’s for your high beams (inner lights), you may need to bend the top (middle) tab down on the bulbs.

H4 Diamond Headlamps

Similar are the H4 crystal/diamond headlamps. These have a totally clear lens with a patterned internal reflector. Good crystal H4’s come with a bulb cover to keep from blinding drivers’ eyes in oncoming traffic. Again, check the legality in your area first. They are also available with black reflectors for a totally different look. These lights are readily available eBay.

H4 Projector Headlamp

Another choice would be projector conversion headlamps. This uses a standard 4×6 headlamp housing and inserts newer projector beam technology inside. We’ve talked to a few people that have tried using them in a Cougar and they didn’t recommend them, as the beam was nearly unusable, but you may have a better experience.

Fast becoming another option is the LED projector conversion headlamp. The combination of a projector lamp with LED accents provides a great look for street and show. Multiple colors are available for the LED accents, and some you can even convert to use as turn signals. Be sure that they are DOT street legal if you’re going to use them for daily driving.

Full LED Headlamp

We now have the luxury of installing full LED headlamps. Obviously there would be no worries about ever changing bulbs again. And the light output is going to be very, very bright. Plus they’ll run a lot cooler than traditional bulb-driven units. They are more expensive than any of the other lamps listed above, but longevity and brightness are good payoffs for the price.


As you know, your headlamps are pretty unique to the car (well, the 1988-94 Lincoln Continental had them too), so there is no swapping of Mustang headlamps into your car, we’re sorry to report. But you can swap out bulbs—carefully.

9004 Headlamp Bulbs

Your stock 9004 bulbs can be replaced by any number of aftermarket bulbs, including hyper-blue, hyper-white and imitation xenon blue. Your local parts store probably has quite a few types on the shelves as you read this. Generally, the better bulbs will be more expensive. You may end up spending $50 US or so to change your bulbs, so be warned. And there is no guarantee that the hotter bulbs won’t melt your headlamp housings. Use at your own risk.

HID Xenon Conversion Kit

You might be tempted to buy a full xenon/HID conversion kit for your headlamps. In theory, xenon bulbs will never burn out and will only need replaced if they’re smashed or damaged. But true xenon/HID setups are amazingly complex and require unique wiring that is much better than what came in your car. The way the system works is that a high-voltage ballast ignites each xenon-filled bulb when the headlights are switched on. The effect is similar to sodium vapor lights used in gymnasiums: initially the lights are dim but rapidly get brighter. Each ballast throws off roughly 20,000 volts, which is enough to do some damage to your body. In other words, this isn’t something you just play around with. You can use an HID conversion kit, which comes with everything you need including wiring, bulbs, and the ballasts. They are available on eBay or through JC Whitney.




The stock side markers are, shall we say, rather large and not congruous with some paint combinations. Unfortunately there aren’t many choices for customization but you can always paint them.

1986 Cougar Side Marker

For this custom side marker, it was simply done by painting over a custom vinyl Cougar logo and the clearcoating it. The trick is to not layer the basecoat on too thick if you want some light to shine through the painted part. Check the opacity of the paint by shining a flashlight inside the marker as you paint. You should find that 2-3 thin coats are about what you’ll need for lighter colors, and 1-2 coats for darker colors.


Again, there are no aftermarket clear markers for these cars. Still, they are semi-clear from the factory which is a good thing, because you can make your own clears if you’re careful enough.

1988 Cougar Side Marker

Start by removing the marker assembly. Using a Dremel or similar cutting tool, hack apart your perfectly good stock marker, then remove the amber reflector from inside. Then seal the whole thing up with copious amounts of silicone, and there you have a custom factory-style side marker. Simple, easy, and best of all, free of charge…if you don’t ruin your marker in the process, that is.

Adding Sequential Turn Signals

The 1967-73 Cougar (along with the 1964-73 Thunderbird and a few Shelby Mustangs) had one of the coolest and most unique features: the sequential taillamps, where the turn signals flash in sequence in the taillights. At the time it was called “gimmicky” but now this cool mod is enjoying a comeback. In fact, Ford brought back the feature for the 2010-up Mustang. The best thing is that it’s part of the Cougar’s history—you need not feel like it’s a passing fad; it’s here to stay. Now until a few years ago, you either had to try and splice in a system from the original Cougar (VERY problematic, and difficult to do), or try to find someone who could build a solid-state control box with Radio Shack parts. Well, thanks to newer companies, you can simply buy the pre-built kit and install it yourself in just a few hours.

1986 Cougar with Sequential Turn Signals

We are not aware of any “plug-and-play” kits for our cars, so that means you’ll need a universal-style kit to retrofit your car. Below is a list of known, quality vendors that sell sequential kits:

  • Cougars Unlimited has created one of the first mass-produced, modern era kits. This is the kit we used because it was the best available at the time. Please check their website for current price information.
  • Web Electric Products sells a universal, low-cost sequential kit that is popular with hot rodders and car enthusiasts of all kinds.



There are a few things you need to know before you buy the kit and begin installation. The kit you purchase will need to work with any vehicle that has 3 brake light/turn signal combo bulbs per side (except those specifically designated as a 2-bulb system). All 1983-88 Cougars and most Thunderbirds have 3 bulbs per side, but one of the bulbs is for marker lights only, not for brake lamps. Which leads to the next point: there is some rewiring and modification to the taillamp wiring harness in order for the 3-light sequencer kit to work. We’ve figured out a way to significantly reduce the need to hack up your stock harness, and those pointers will be made below.

What comes in the kit?
The kit consists of a control box, wiring harnesses, mounting screws, a new heavy duty flasher, and instructions.

How does the kit work?
In a nutshell, the control box acts as a central brain or junction box for the brake signals and turn signals that go to the rear taillights. With this system the box controls everything automatically; this is why you need to do the rewiring. Also, you will replace the stock flasher with the special heavy duty unit supplied by the kit.

What do I need to start?
Basic hand tools (wiring strippers, screwdrivers, sockets), electrical tape, butt splice connectors, and 6 additional taillight bulb sockets (if bypassing the stock harness). A test light is also very handy to use here.


The following photos are a step-by-step tour of installing the Cougars Unlimited sequential turn signal system. It may or may not be similar to other kits. This section is only meant as a supplement to the instructions that come with the kit. You assume responsibility for any actions herein.

NOTE: All photos are taken from a 1986 Cougar. Your car’s setup may vary from the car shown.




Sequential Turn Signal Install

After disconnecting the battery, remove the trunk liner (if applicable). This is the stock wiring harness, driver’s side, for a 1985-86 Cougars. Sockets from left to right: backup lamp, lights-on marker (inner), turn signal/brake lamp (middle), turn signal/brake lamp (outer). Your bulb order may vary, but you do have the same kind of sockets regardless.


Sequential Turn Signal Install

This is the stock wiring harness, passenger’s side, for 1985-86 Cougars. Sockets from left to right: turn signal/brake lamp (outer), turn signal/brake lamp (middle), lights-on marker (inner), backup lamp.


Sequential Turn Signal Install

This is the Cougars Unlimited kit: both wiring harnesses, signal box and flasher. You should mount the box somewhere out of the way where no wiring will rub against metal, and also where it will be protected from water.


Sequential Turn Signal Install

This box was mounted behind the driver’s side trunk liner panel, on top of the wheel well. Since most of the stock taillamp wiring is on this side, it’s a logical choice and out of the way of objects in the trunk. The box is being held down by simple zip ties. It’s okay to make a custom mount for the box, if you wish. All wiring was tucked into wiring loom after the install.


Sequential Turn Signal Install

In order for the kit to work, you need 3 brake lamp/turn signal sockets on each side of the car. For 1983-84 Cougars, you have to convert the outer marker lamp over. For 1985-88 Cougars/T-Birds, you have to convert the inner marker lamp over (next to the backup lamp). The hole above can easily be cut with a Dremel tool or sharp knife. The trick is to get the hole to look like the hole next to it…


Sequential Turn Signal Install

…just like this one, so obviously you have to make the other hole bigger. Neatness does count for the most part, although it’s possible to be a little off. So long as the bulb socket goes in, turns, and locks, you are good to go.


Sequential Turn Signal Install

This is step 1 for the taillight socket hole. It’s simply rounded out with a Dremel tool and sanding disk.


Sequential Turn Signal Install

After cutting up the rest with a utility knife, this is what the hole more or less will look like. Make sure to double check the bulb so that it doesn’t pop out accidentally. If you do take too much out, you’ll have to fill the area with JB Weld and try again.


Sequential Turn Signal Install

Instead of hacking up the stock taillight harness for the wires, you have a better option: buying new Ford taillamp sockets, as shown here, and splicing them into the wiring for the control box instead. You’ll need 6 total, 3 for each side, and it doesn’t matter if the sockets are for the 1157 or 2458 bulbs—your call there. This way you can preserve your stock wiring harness in case you ever need it again. You will still need to use the stock wiring harness for the backup lamps (and side markers on 1987-88 cars); the other sockets will simply need the bulbs removed. There is enough room at the bottom of the trunk well and behind the taillight panel cover of the trunk liner to let the wiring just hang.



1) Disconnect the battery before attempting to install this kit.

2) When connecting wires, use butt splices or solder all connections. The principle behind this box is that it bypasses the stock wiring for the turn signals and brake lamps. In other words, all faith is put into this box. Therefore all wiring MUST be secure and permanent or else you run the risk of losing your brake lamps and/or turn signals as you drive. And make sure that no wiring will get in the way of moving parts (i.e. brake pedal).

3) There are two wiring harnesses associated with the box: one is for power input, the other is for power output. The input harness is where you should start first. For that, you will need to get a pure brake signal, and a pure turn signal for both left and right signals. NO CHEATING HERE. If you own a 1986-up vehicle, the brake signal can come directly from the third brake lamp in the rear window. For all pre-1986 cars, you MUST run a wire all the way up to the brake switch on top of the brake pedal (green wire), as there is no other place in the car to get this signal.

4) For the turn signals, all cars must get the signals from the switches on the steering column. You don’t have to strip the wires on the column or for the brake lamp; you can use a simple Scotch-Lok connector to piggyback those wires. Wiring may vary from car to car so you’ll have to get the signal yourself. To get the signals you will need a test light. Remove the steering column cover. Temporarily connect the car’s battery and carefully turn the key forward, but do not start the car. Put the driver’s side turn signal on, and test the wires in the turn signal harness on the column. You should find that one wire flashes the test light—that’s the wire you will need to hook up to the box. Repeat the same for the passenger side signal, then disconnect the battery again. Piggyback the wires and run them to the box. It’s easiest to run the wires underneath the carpeting along the driver’s side of the car.

5) Once all the input signals are taken care of on the box, go to the other harness for the lamps. Each socket will have 3 wires going to it: one for the brake/turn signal, one for the lamps on, and one for the ground. It’s helpful to chain all the grounds together, then to one master ground (either a ground wire or bolted to metal). You will also need to chain all the lights-on wires, tapping power from one such wire from the main taillight harness. Take your time and follow the instructions carefully. Once you have all the output wires situated, plug both harnesses into the box.

6) Before you reconnect the battery, you must change the flasher under the dash to the new heavy duty unit. This is because you’ve added more sockets to share the signals. If you were to use the stock flasher, the sequencer would work too fast and you’d lose the effect. The provided heavy duty flasher slows down the signal to the box and lets it sequence perfectly. After changing the flasher, reconnect the battery—it’s time to test the turn signals and brakes. A helping hand is good here.

7) Hopefully you’ll get the sequence in the first shot. If not, you’ll be checking the wiring extensively. Be patient! Once you’re working fine, double check all of your connections, then properly secure all wiring away from metal and out of the way.

Adding Electroluminescent Coach Lamps

When the aero Cougar first appeared in 1983, a few critics noted that the car had some holdovers from previous Cougars that dated the new body style, such as the stand-up hood ornament, ultra-plush LS velour interior, and the exterior coach lamps. Now here at COOL CATS we have always loved those coach lamps. And all these years later, electroluminescent coach lamps have seen a comeback with import tuners. We were definitely ahead of the trend! If you’ve always wanted the Cougar’s coach lamps for your car, but it never came with them, this section will help you with information and installation.


1984-86 Cougar Electroluminescent C-Pillar Emblem

The factory electroluminescent coach lamps were standard on all 1983-86 Cougar LS models, and 1983-84 base (GS) models that had them as an option. No XR7 model had them, and no post-1986 Cougar had them. Here’s how they work: inside the emblem’s tan-colored casing is a miniature power inverter that works off 12v. The inverter is attached to a thin electroluminescent plate via two copper bands. When lit, the plate will emit an audible hum or whine. On top of the plate is a light diffuser, which helps to distribute the light evenly, and then the top acrylic Cougar logo. The acrylic is glued to the casing from the factory. The entire assembly is held to the car via a metal retaining ring with rubber on the back to prevent water infiltration. The ring has 3 prongs on the back side, which go through the car’s rear quarter panel, and attach inside with aluminum quick-nuts. The bolt pattern for the ring favors the 1983-86 cars, as the bolt pattern shrunk just enough not to make these usable directly on 1987-97 cars.

The hardest part about the EL coach lamps is actually finding them. They are not sold at Ford dealerships anymore, and NOS lamps go for big bucks on eBay when they’re available, which isn’t often. Used units do show up on eBay, albeit very rarely. You may have to go hunting at swap meets or the local salvage yard. Remember, there are plenty of 1983-86 LS owners that are looking to replace their burned-out lamps, so the competition will be fierce. Also don’t forget that you will need the EL lamp assembly as well as the retainer (trim) rings to hold them in—both are necessary.


If you acquire a set, the first thing you MUST do is test them, so that you don’t end up drilling holes in your car for nothing. The lamps invert the power off 12v DC, so usually you’d just hook up the power (brown) and ground (black) wires to a car battery to test them. However, a neat trick is to carry a 9v battery with you and test the light out on that. It won’t show at full brightness but you will be able to see if it does light up at all, and you should hear the inverter hum a little. If so, you know you’ve got working units at least, and you’re ready to install. If not, see the Troubleshooting section below.



Installing the coach lamps is not terribly difficult, although you do need to drill a hole in your perfectly good rear quarter panel to mount these lights. Start by removing your interior sail panel, remove the black insulation panel underneath it, and there you have the quick nuts for the original Cougar emblem. Remove the nuts and the emblem should just pop out; if not you may need to gently pry the emblem off the car.

Notice the two small holes that are directly opposite each other (the third hole is for the guide pin on the emblem). Find the exact center between them and make a mark. Then, using a 1″ hole saw, drill the new hole. This large hole is necessary because the electro coach lamp casing has a shaft that contains the power inverter; you cannot get around this. It is usually okay if you’re not exactly in the center, but you don’t want the casing to touch the metal, or else the acrylic outer cover will crack with road vibrations.

You will need to apply some type of gasket on the back of the electro emblem before installation. A hand-made rubber gasket or silicone will work; even electrical putty is fine. The trick is to completely eliminate the chances of water entering the new hole you just made. Also, you may wish to treat the bare metal around the hole with paint to prevent rust. Remember that this part will not show so feel free to use anything, like touch-up paint or even nail polish. Tighten up the nuts inside the car, and the emblem is officially mounted.

Now you need to find some electrical power for the lights. From the factory, these lights required the interior reading lamps for the back sail panels, because both worked off the same wiring harness. It’s impractical to find and use this harness. Your best bet is to run the wiring from the lamps to the trunk, and tap into the marker lamp (not a brake/turn signal lamp). These coach lamps require very little power so you don’t have to worry about any type of power drain. The electro lamps have a simple two-wire hookup: power and ground. If you can clip the harness end and some of the wiring from a donor car, this is a plus. Otherwise you can use simple speaker clip connectors. After the wiring is completed, try them out, reassemble the interior, and you’re finished.



So what happens if your lights don’t work, and you’re positive that the wiring is correct? Well, that’s the gamble you take with old units. The problem with these lights is that they’re well over 20 years old and will stop functioning sooner or later. The inverters seem to be the problem. Once they’ve lived their useful lives, they will no longer transfer power correctly, and the light will flicker and cut out. Also, a very loud high-pitched whine can sometimes emanate from the lamp when they’re about to die. Eventually the inverter quits altogether and the lamp will no longer light up. The inverters do have a Ford part number stamped on them, but that number is obsolete and the chances of finding any older inverters laying around is slightly less than a snowball’s chance in Hades. In this case you have three options:

  1. Live with them not working.
  2. Disassemble them and install a regular light bulb.
  3. Find a way to install a new electroluminescent plate and inverter.

(We’ll assume that option 1 is not an option at all.)


EL Lamp Bulb Replacement

Some people have gone for option 2 and have cracked open their lamps, removed the inverter and electro plate, and installed a simple Ford factory bulb holder and bulb. This is good because it’s a replaceable bulb. But bulbs do not distribute light evenly, which is why they weren’t used in the first place, so the electroluminescent effect is totally lost. You can try using a piece of scuffed-up Plexiglas, or even frosted Lexan, to help with light diffusing. It’s about the cheapest and most practical way to keep the lamps lit, although it’s not going to have the same effect.

Option 3 demands that you put a new electro plate in there. It may be possible to pirate parts from one of the newer import car electro emblems and reuse them in your coach lamps. Don’t forget that technology has changed dramatically in the last 20 years—newer electro emblems have much smaller power inverters. You can also do a search on the Web for companies that sell electroluminescent lighting. This is an option that can definitely work, and will definitely get the correct look back.

Stephen has written and reported this:

“I read your part about the electroluminescent coach lights, and I have some new info for you. The newer EL stuff is available as a complete experimental kit from an electronics parts supplier, All Electronics Corp. The kits run about $24 US for a complete kit. I found them doing some research for my other hobby, rebuilding and building custom dashes and gauges. I plan to use my existing emblems on the sides to make my own EL coach lights.”

Taillamp Modification

Cougars are great for doing taillight modifications. No matter what year Cougar you have between 1983 and 1988, there’s always something that can be done.

But first we have to dispel some rumors. Smoked taillight covers don’t exist for these cars. Never have, probably never will. There are a number of reasons why, but most of all because the cars are so old now. Besides, the 1985-86 cars had factory smoked taillights. Do not expect to ever find smoked covers unless somebody has made a set out of their garage. We’ve tried before and it’s not easy to do because of the compound curved surfaces.

Also, it is not possible to swap 1983-86 taillights for 1987-88, and vice versa. And you cannot use Thunderbird lights in your Cougar. Nothing between all of these lights is common besides the light socket locations, and even those vary greatly. The shapes, angles and mounting points all vary between cars and body styles. The only way to get any of these to work would be to do some major welding and bodywork. Really, because of the metal taillight mounting panel differences, it’s not even easy to swap 1983-84 taillights into 1985-86 cars (and vice versa). It can be done but it’s not pretty and it’s definitely not simple.

So you’re kind of stuck with what you’ve got…but that’s not necessarily a bad thing, as you’ll see below.



These taillights got the short end of the deal as far as customizing goes. They do look sort of trick as they are, and they fit the lines of the car nicely. Still, if you want to be different, there’s not a whole lot you can do besides blacking them out (see 1987-88 section below). You can also paint the cat head in the backing light a different color, as well as the stripes between the tiers. Wax and grease remover will take off the chrome from those areas quite nicely, leaving a clean look. Unfortunately there’s not much else that can be easily done.



Now these taillights are much better for customizing because of their flat surface. If you’re looking for something other than a straight blacked-out look (see 1987-88 section below), here are some cool tricks.

1985-86 Cougar Taillight Mod

How about some cool 1987-88 Thunderbird-style round taillights for your Cougar? All you need to do is create a mask that’s sandwiched between the outer lens and the housing. To remove the lens simply pull on it gently; take your time because you can easily crack the lens if you’re too rough or impatient. Doing this on a very hot day with the car out in the sun will help a lot. Once the lens is off, cut some material to use as the mask. Thin black foam found at craft stores works great because it’s water resistant and easy to cut. Find the center of each square in the housing, then mark that center on the foam. All you need to use to cut the circles is tracing around a roll of masking tape or similar sized object. After the mask is completed, simply use black electrical tape to attach it to the lens, then put the lens back on the housing. Can’t be simpler, and the effect is so similar to the cool round T-Bird taillights that people will do a double take.


1985-86 Cougar Taillight Mod

This is about as tricked out as we’ve seen for 1985-86 lenses, painted with the early 1990s Mercury signature “laser stripe” motif. Essentially this gave the lenses a retro look, similar to the original Cougars in the 1960s. In addition, the backup light area was painted with the Cougar logo, resembling 1987-88 Cougar taillights. Then the nomenclature was removed from the bottom reflectors, their indents filled in, and the reflectors painted body color. Everything was then clearcoated with automotive urethane clear for a nice, bright finish and durability. Now you don’t have to be a painter to emulate this…the basic striping can be done with vinyl, which also makes removal a possibility if you don’t like them anymore. A body shop could help with the taillight reflectors and clearcoating. The possibilities are endless…use your imagination.



With the new body style came new taillights, and these are pretty cool and easy to modify.



1987-88 Cougar Taillight Mod

Ever been jealous of 1996-2004 Mustang owners because of their clear red taillight lenses with clear bulbs? Well, envy no more because you can emulate this look very easily on your 1987-88 Cougar. Best of all, this trick is free of charge. All you need to do is remove the factory reflector inside each lens. This is okay because there will still be a reflector around the backing light when finished, so you will stay legal.



1987-88 Cougar Taillight Mod

Start by gently pulling on the lens until it comes off, leaving the housing on the car. You may want to do this in warm/hot weather, or in a well heated garage, so you don’t risk cracking the lenses.


1987-88 Cougar Taillight Mod

Here is the lens off the car. You’ll notice that the whitish-colored reflector is attached to the lens. It’s not glued on but rather attached at several points with heat, which melted the two parts together. The “welds” are strong enough for daily driving, but gentle enough to allow the lens to come off. Firmly pull the reflector off, one weld at a time, carefully using constant pressure.


1987-88 Cougar Taillight Mod
When the lens pops completely off, this is what you’ll end up with. We recommend saving the reflectors in case you ever need to reinstall them.


1987-88 Cougar Taillight Mod

Lo and behold, upon reassembly you have a clear red lens, just like some newer Mustangs.


1987-88 Cougar Taillight Mod

This is a before-and-after shot. The left lens has had the reflector removed; the right one is still stock. During the daytime there isn’t a dramatic difference from a distance but you will notice it up close. At night, the stock clear bulbs are really, really, REALLY bright without the reflector in there. You may want to consider using red-colored bulbs or doing something to tone down the light a bit, so that you don’t have any unwanted law-enforcement attention.


1987-88 Cougar Taillight Mod

1987-88 Cougar Taillight Mod

sarjxxx has provided photos of this mod on his own car. Note the absence of black in the center section. This may or may not create unwanted blinding to the cars behind you so please consider that.


By far this is one of the most requested taillight mods for any 1983-88 Cougar. Before you start, consider that a blacked-out lens is illegal in some places. This is because of reduced light transmission and a general dark lighting situation. Do this mod at your own risk.

The usual product used to create this effect is called Niteshades. You can find it at your local parts stores or online. It’s a liquid that you spray onto the outside of the lens for a permanent smoked look. It will take about 5-7 thin coats per lens to get the desired effect.

Nite Shades Application

Start by removing the lenses. Wipe the lenses down with rubbing alcohol or wax/grease remover and let air dry. Then run a tack cloth over the surface to get any debris off. You’re now ready to spray away. This stuff is pretty tricky because if you put too thick of a coat on, or if the previous coat hasn’t dried enough, it will sort of push the previous stuff away and generally look nasty. Or it can run down and make a real mess. Take your time and put thin coats on. When finished, they should look similar to the car at left.

Nite Shades Application

Here’s the same car with the lights on at dusk. In this photo they look pretty red. In reality these are darker, and in the full darkness of night they will appeared smoked.

Instrument Cluster Swap (1985-88)

One of the most popular questions we get is, “Can I swap out instrument clusters in my 1985-88 Cougar/T-Bird?” Well, the answer is “yes” but it’s not a straightforward, plug-and-play situation. Unlike cars of today, there wasn’t really a lot of foresight when planning the wiring harnesses on these cars. Then again, there were a LOT of options and trim levels available, so it was never likely that anything would be engineered for a swap in the first place. That doesn’t mean it can’t be done, though.


1988 Mercury Cougar XR-7 Dash

There were three types of instrument clusters for these cars from 1985-88: the base (standard), full electronic, and analog. Of these, the analog seems to be the most desirable because it displays full instrumentation very easily. A lot of people like the full electronic cluster as well, but it’s a long and arduous trek to install one of those into a car. Most people seem to want to step up from the base to the analog, or from the full electronic to the analog.

So how exactly is the swap done? In a nutshell, once your existing cluster is loosened, you will have at least one wiring harness attached to it (the base and full electronic have two). Whichever stock-style cluster you’re installing will require different wiring. This means you will need to rearrange the wires inside the harnesses to work correctly with the new cluster. This is known as repinning and it’s not really that difficult to do. After that is done, the new cluster can be installed and tried out.

Of course, there are a few caveats to this swap. For instance, analog gauges use different sending units so those would likely need swapped out (and that could include the fuel sender in the tank). You may lose your the shift indicator in the new cluster. You may have to run some new wires to pick up the tachometer signal. The tachometer may need additional calibration in order to work correctly. So be prepared for some extra work if you’re going to do this.

We have prepared several conversion guides to help you do the conversion—see the download links below. Also, we have provided the wiring specifications for all three harnesses on this page for your convenience.

For an instruction manual on swapping from the base to the analog cluster, download the PDF file here.

For an instruction manual on swapping from the full electronic to the analog cluster, download the PDF file here.

4-to-6/8 Cylinder Analog Tach Conversion


If you’ve swapped over the full analog instrument cluster to your car (or are thinking about it), one of the main roadblocks in having that “perfect” setup is the tachometer. There were two different tachs: one for the 4-cylinder turbo engine (7,000 rpm), and one for the V8 (6,000 rpm). You’ll find that the V8 tach is fairly difficult to find, and you’re probably wondering if there’s a way to convert a 4-cylinder tach over to read accurately for a V8 or V6. This section will help you do just that. Thanks to Tom for the information.

IMPORTANT: This mod is for 1987-88 4-cylinder tachometers ONLY. It WILL NOT WORK on 1985-86 4-cylinder tachometers. If you want to do this mod and you own a 1985-86 tach, so far no technical solution has been made. Currently the only solution is to switch over to a 1987-88 tach and reuse your stock face, or use a 1988 V8 tachometer.


4-to-6/8 Tach Mod

“These tachometers simply react to the pulses fed to it, thus the reason for tachs calibrated for 4 or 8 cylinders. Mustangs had a convenient 4-6-8 switch that allowed instant calibration; our cars were not that fortunate. The 4-cylinder tach will read double the rpms in a V8. There is only one resistor that is different in the Turbo Coupe vs. the V8 tach. It is located near the minus (blue) wire to the tach movement. It is 100k ohm. Changing it to a 75k for a 6-cylinder or to a 50k for an 8-cylinder should be close. The resistor is a 5% tolerance, as noted by the gold end band. Anything between 95k and 105k is still in spec. Either add another 100k across it in parallel or replace it with a 51k (50k is not a standard value).”

140mph Analog Speedometer Conversion


One of the most requested changes to our cars is that people would like the stock analog speedometer to read higher than the stock 85mph (even though technically the ticks go to 95mph). This section will help you modify the electronics of your speedo to be calibrated for 140mph.

First a little background on the stock speedometer. Remember that these cars existed in the 1980’s, when insurance rates were very high, and speed-rated tires were only available on a select few vehicles. Most vehicles from that era had speedometers that did not read past 85mph in the United States. Bowing to government pressure, Ford did this with our cars as well (with both analog and digital speedos). Owners were pretty much stuck with the stock configuration.


Fact vs. Fiction - 140MPH Motorsport SpeedometerHowever, there is an actual Ford 140mph speedo that was available for our cluster. It was not available at Ford dealerships, but rather through an authorized Ford Motorsport dealer. The legendary Ford 140mph speedometer simply dropped right in—no calibration necessary, and no extra wiring needed. Brand new the 140mph speedo listed for $150 US. It’s been discontinued since 1993, and if you can find one used, they still command a pretty healthy price. So if you want an actual, genuine Ford Motorsport 140mph speedometer unit, you will definitely have to reach deep into your pocket—if you can find one.

Recently a very informative message board thread brought up the possibility of converting a stock 85mph speedo over to one that reads higher. Through a collaborative effort, it was discovered that one resistor change is all that’s needed to accomplish this. After the physical change, a new speedometer face is all that’s needed to complete your conversion.

One item of concern is that the new speedometer can read lower than actual speed at speeds below 40 mph, remain fairly accurate from 40 to 100 mph, and then read higher than actual at speeds higher than 100 mph. The greatest amount of “drift” is about 10 mph, which means that the speedometer may only show 25 mph when the vehicle is actually traveling 35 mph. If low speed accuracy is a major concern for you, these speedos can be recalibrated with the use of special equipment, namely a wave function generator and a Hz meter. There is a large center weight on the armature of the speedometer that will either have to be moved inward or outward to take care of the low and high speed inaccuracies. It’s also possible that a 1K resistor soldered in-line may also help correct it. If a feasible solution is found it will be posted on this page at a later date.

Now the physical changeover of the speedo from 85mph to 140mph is fairly simple. But by no means does it imply that your car will actually attain those speeds. This mod is simply to make your car have a simulation of a rare piece and does not warrant excessive speeding for usage!

This article was written and compiled by Joe—much thanks to him and to all the message board members who made this mod possible.



  • Basic tools (screwdrivers, pliers, sockets, wrenches, etc.)
  • Soldering gun or stick
  • Soldering wire
  • One (1) .033µf (aka 333K) radial metal film capacitor. If you can’t find one out of a junked radio or similar, you can order a set of them from Digikey, part # BC1650-ND. The price is about $1.00 U.S. for 10 capacitors
  • Some type of clear spray paint—flat would be better than gloss
  • Adhesive-backed printer paper
  • Something to cut out the face: razor blade, X-acto knife, etc.
  • Black magic marker (Sharpie), if making a black faced speedo
  • Rubber cement, spray-on adhesive, super glue, or something similar
  • 400 grit sandpaper
  • Styrofoam plate (optional)

The speedometer must be removed from the cluster in order to do the conversion. Start by removing the six black cover screws. Once the screws are removed, you should be able to take off the clear cover and the black plastic cover. Now it’s time to turn our attention to the back side of the gauge cluster. The speedometer is held in place by 6 screws on the back of the cluster, 3 gold screws and 3 tiny black screws. Be very careful when working—you DO NOT want to damage the printed circuit. Once you have removed all the screws, you can now remove the speedometer from the cluster.



Now remove the needle from the speedometer. It is pressed on the shaft, but should come off by pulling straight up on it. This may take a while, so be patient. Twist off the extension to the trip reset. Now remove the 2 black Phillips head screws on the speedo face. You can now remove the face.



To get to the circuit board a screw must be removed on the back of the speedometer. Once the screw is removed the circuit board should be free to separate from the odometer/armature assembly.

The capacitor that will need to be changed is marked “473K” in the “cv” position. It is not only soldered in place, but also glued to the board. Unstick it from the board. Using a soldering gun, heat one of the factory solders while pulling on the capacitor on the other side of the circuit board. When you feel the cap move a little, heat the other solder until the cap moves again. Keep alternating the solders until the cap works its way out. Take the new capacitor and put it in place of the old one. Heating the solder while pushing on the cap will allow it to get through the holes. Once the new capacitor is in far enough, determine whether or not the old solder spots need more solder. If they still look adequate, leave them be. Put the circuit board back onto the odometer/armature assembly.



NOTE: This section relates to completely changing the speedo face. If you wish to just cover up the old face with a new sticker, skip to “Printing the New Speedometer Face” below.

The first thing to do is remove the old face. Using a precision screwdriver, get underneath the old face and slowly pry the face up in various places. If you’re having trouble with this part, placing the face over a pot of boiling water may help to soften the factory adhesive and allow for easier face removal.

Now it is time to sand off the old face to make way for the new one. By sanding off the old face, we can still use the factory green light diffuser for a more stock appearance (you can put the face on the back of a styrofoam plate to assist in the sanding process). Keep sanding until all the black and white are removed from the green disk. Clean all the sanding debris off the disk.



The printing and cutting out of the face is next. You can find a complete list of speedo and other gauge faces in the Media section of this site. Simply select which style of speedo face you would like to use and download it. Open it open in MS Paint, Photoshop or equivalent program and it should be the right size. Then simply print out the face on the special adhesive-backed paper.

Before handling the face, spray the clear paint on it, giving it a light, even coat. This will protect it from fading from UV light and from smudging while you handle it. Once the paint has dried, cut out the inside details on the face, then the outside perimeter. This way you have something to grab onto besides the face itself while you cut out all the little rectangles and circles. If you are making a black face, now is the time for the Sharpie. Use it to touch up all the “white border” you get from cutting out those rectangles.

Once you have the face cut out, peel of the cover for its adhesive backing, and very carefully center it on the green disk, making especially sure the odometer rectangles are lined up correctly. Slowly work the face onto the disk, starting from the center and traveling outward to prevent air bubbles. Apply some adhesive to the perimeter of the back of the disk, and put some around its center hole. Press it back onto the clear plastic plate and wipe up any excess adhesive that might squish out.

All that’s left is to put the speedometer back together and to put it back inside the instrument cluster. Now go out and enjoy your 140 mph speedometer!

199mph Digital Speedometer Conversion


Thanks to Joe (bondocougar) for his amazing work and willingness to share the knowledge on this project.

One of the most requested changes to our cars is to make the stock digital speedometer read higher than the stock 85mph. Until recently it was not known if this was possible, but thanks to a spirited discussion (and lots of trial and error) on the message board, we now know that this can be done. This section will help you modify the electronics of your speedo to read to 199mph. Please note that this only affects the part of the module concerning the U.S.-calibrated MPH reading; when the module is set for KPH the reading will still only go to 199 kph.

First a little background on the stock speedometer. Remember that these cars existed in the 1980’s, when insurance rates were very high, government regulations were coming in faster and faster, and speed-rated tires were only available on a select few vehicles. Therefore most vehicles from that era had speedometers that did not read past 85mph in the United States (with both analog and digital speedos). Owners were pretty much stuck with the stock configuration unless they added an aftermarket speedometer.

Now you don’t have to! All you need to do is remove your instrument cluster, then focus on the middle speedometer module. You really don’t need to disassemble the entire module from the cluster; in fact, the work can be done with the module still bolted in. All you need to do is find the W2 on the circuit board, and solder a jumper wire between the two contacts at W2. It’s really just that simple! Reassemble the cluster and reinstall in the car, and enjoy!


199mph Speedo W2 Mod

The physical changeover of the speedo from 85mph to 140mph is fairly simple. But by no means does it imply that your car will actually attain those speeds. This mod is simply to make your car have a higher reading and does not warrant excessive speeding! Please see our disclaimer for more information.

"S" Removal from Digital Speedometer


Thanks to Stephen for this information.

If your digital speedometer constantly displays an ‘S’ in the space underneath the speed display, that indicates that at some point your speedometer module was replaced under service at the Ford dealer. There technically should be a sticker affixed inside your driver’s door jamb to indicate this.

199mph Speedo W2 Mod

To remove the “S”, you will need to remove the cluster from the car. Following the same general information used in the 199mph speedometer modification, along the same side of the board are several jumpers at W3 & W4 that can be removed or cut. These will permanently remove the “S” from your display. Then reinstall the speedometer and dash cluster to test. Enjoy!

Custom Gauges

Many of the things we have today didn’t exist or were too expensive to produce during the 1980’s. One of the glaring areas of our cars where corners seem to have been cut was with basic instrumentation. This section will help you with customizing or adding gauges to your car.

But before you go out and plunk money down on aftermarket gauges, think carefully. Know which gauge(s) you want first. Is your car lacking a temp gauge? How about oil pressure? Maybe an air/fuel mixture gauge? Also, keep in mind that while having aftermarket gauges is way cool, they won’t do you a bit of good if you can’t see them. Keeping them in your line of sight is obviously the goal, but with some interiors this is a difficult task. We’ll help you with the best solutions below.



Let’s face it: your dash layout leaves a LOT to be desired. In the base configuration you only a fuel gauge and a speedometer, and a warning light for the engine and brake, and that’s about it (although if you owned a 1984 XR7 you’d also have a tachometer). Ford didn’t have a whole lot of money to put into your interior when they restyled the car for 1983; as a result, the instrument cluster got the proverbial short end of the stick. To say that you have minimal instrumentation would be an understatement. While it’s not really practical to modify your existing dash cluster, you can still modify all around it.

Most people long for a tachometer. A simple column clamp-on tach would work, although it does tend to block the view of some of the instrumentation. A few people have removed the clock and stuck one there—a great solution if you don’t need the clock, or if your aftermarket radio is equipped with one.



1983-84 Tachometer1983-84 Radio Panel Gauges

Your dash is limited as far as placement of other gauges (temp, oil pressure, etc.). One option is to mount them on the lighter panel, although this is not in your line of sight, particularly with a floor shifter. Another option is to mount them on the passenger side of the dashboard, facing toward the driver (similar to what Fox Mustang owners used to do). There should still be some aftermarket mounting panels for 1979-86 Mustangs that you can use. This works just fine if you indeed wish to do that to your dash.


A-Pillar Gauges

The easiest solution is a bolt-on Auto Meter A-pillar pod. Currently a 1994-2004 Mustang pod is about the best solution as far as fit and finish. As of this writing there are no complete A-pillar replacement pod panels for your car.


1983-84 Pro Street Gauges

This is a completely custom gauge cluster, made for a pro-street style Thunderbird. Obviously this would be the best solution although it does take some extensive modification to work.


1983-84 Pro Street Gauges

Here is another pro-street T-Bird with custom sheetmetal for the dash, and all the gauges where you’d expect them to be.



With the money Ford made off the 1983-84 cars, a new interior was ordered for 1985 (which continued through 1988), so new instrument clusters found their way into our dashboards. There were three types of clusters: base, full digital, and full analog. Here are some tips for adding to and/or modifying your gauges, no matter which type you have.


Electroluminescent Gauges

Lucky owners of full analog clusters can modify quite a bit. Matt custom produces custom gauges overlays for our cars, and can even make Indiglo-style overlays. His work is outstanding, and after seeing it in person, we can vouch for his attention to detail. He will custom-produce anything you wish. Contact him here.


Digita Color Gauges

Got a full digital dash? How about some custom colors instead of spinach green? This involves the disassembly of the cluster, and basically laying colored plastic or tape over the green areas, then reassembling. A very thoughtful and refreshing mod, to say the least.


1985-88 Triple Gauges


Your radio panel is a godsend, with 4 slots instead of the 1983-84’s 3 slots. If you’re not using your storage bin or EQ over the radio, ditch it for a custom panel and some aftermarket gauges. You can fit several 2 1/16″ gauges easily in this area. If you have a console, you can also mount gauges in your lighter panel.


1985-88 Clock Tach

Again, removing the clock and sticking a gauge or tachometer there is an option. We’ve even seen people remove a heater vent or two and shove gauges in there. Your dash is a veritable playground for custom gauges….go wild.

By the way, you can get a custom clock gauge mount at


1985-88 Passenger Dash Gauges

How cool is this?! Obviously you’d be cutting up a perfectly good dash, and from the looks of things, the line-of-sight on these gauges would be quite cumbersome. But it is a solution.



Quality manufacturers of aftermarket gauges include Auto Meter, VDO, Dakota Digital and Nordskog among others. Since they sell so many, the cheapest and most plentiful places to find these gauges are Summit Racing and Jeg’s.

For our cars, the easiest type to use, by far, is the electrical kind, which either works off your stock wiring or requires a sending unit change to receive an electronic signal. They’re generally very accurate and usually come with a provision for internal lighting at night. Wiring them in is pretty simple too. Electrical gauges come in analog style or digital style, so you can match or contrast your stock gauges perfectly.

If you’re seriously old school, you can use a mechanical gauge on these cars if you’d like, but be very careful. Mechanical gauges are directly connected to an engine or other driveline liquid under pressure via custom tubing. They are extremely accurate and are legendary for reliability and performance, as well as a usually lower price vs. electrical gauges. However, in most instances you cannot mount these gauges inside your car unless you have some type of signal converter in place before the firewall. In the United States, by law you are not allowed to have flammable liquid enter through the firewall for safety reasons. This means fuel, transmission fluid, oil, and so on. You are allowed to have a mechanical temp gauge inside the car. Some people like to mount mechanical gauges on their hood, right in front of the driver. Some just leave them under the hood, out of sight. There are inherent problems such as this when using mechanical gauges, and you should use one on these cars only if you absolutely need one, or if you know what you’re doing.

Don’t forget that from 1985-on, these cars had full electronic speedometers that fed off a signal from the speed sensor (VSS) on the transmission. This makes installing an aftermarket eletronic-driven speedo a blessing. Inversely, 1983-84 cars had a cable-driven speedometer. Using an electronic speedo in these cars would require a VSS installation (1983) or custom wiring to tap into the existing one (1984). From what we understand, the new speedo won’t register correctly under 30mph for some reason. Installing a 1K resistor inline seems to solve that problem. You can always add a regular old cable-driven speedo as well.

Finally, we’ve provided a template below for 1985-88 cars with the analog cluster. If you would like to keep the cluster but just add aftermarket gauges, this template will help you cut out an aluminum or plastic overlay in which to install the gauges. Keep in mind that this does require cutting up the white (back) part of the cluster, and removal of the factory flexible circuit board, plus extensive rewiring of the cluster.

For a template to use on the analog cluster, download the PDF file here.

Tripminder Installation

Thanks to Sajeev for the information in this article.

The Ford Tripminder computer was a forefather to the modern digital interface systems of today’s automobiles. Though computers weren’t exactly affordable in the early 1980s, Ford decided that their more premium automobiles should have an optional computer to showcase its new engine technology. This computer shows you month/day/time, elapsed time, average MPG, average speed, instantaneous fuel economy and gallons of fuel used. By the late 1980s, computers were not that unique, therefore Ford decided to remove the Tripminder option from many cars—including the 1987-88 Thunderbird and Cougar—in order to cut costs.

Ford Tripminder

Sajeev writes, “After over a year of working the bugs out, I installed a Tripminder from a 1983 Heritage Thunderbird into my 1988 Cougar XR7. You would want to add this to a Cougar if you have the analog performance cluster or the standard cluster. Once installed, your dash will have all the benefits of the optional all-digital cluster. The Tripminder replaces the standard clock (digital or analog) in the center of the dash.”



  • Functional Tripminder computer with its connector and wiring
  • Fine grit (around 800) sandpaper
  • 4mm deep socket for a 1/4″ drive ratchet
  • A good cutting and crimping tool
  • Tap splices (2) and butt connectors (6-7)
  • Extra 14 or 16 gauge wire, two different colors preferred
  • Electrical and Vacuum Trouble Shooting Manual (EVTM) for your vehicle (HIGHLY recommended)

The hardest part of the install will be actually finding the parts. We cannot give an exact breakdown of which year Fords had the optional Tripminder, but it is from about 1980 to 1989.

  • 1980-1989 Crown Victoria/Grand Marquis
  • 1980-1982 Thunderbird/XR7
  • 1983-1986 Thunderbird/Cougar
  • 1983-1986 LTD/Marquis

The Crown Victoria Tripminder has a different mounting bracket than the Fox body Fords, so you will either have to modify it with the brackets from your clock or use it for spare parts. For 1985-88 Cougar owners, the ideal Tripminder unit will come from a 1985-86 T-bird/Cougar because of its green display color. The other lenses will be bluish, but it still looks fine with everything else in the dash.

If you see a Thunderbird Heritage, Fila, Elan or a loaded Cougar LS in the salvage yard, odds are it will have the Tripminder.

Cut the Tripminder loose with its connector on the back intact. Take a look at the wires on the back of the Tripminder. Notice how there are more pins in the harness than there are wires. Here are what the pins correlate to and their wire colors:

  • Pin 1: EMPTY
  • Pin 2: EMPTY
  • Pin 3: Ignition Power (light blue/black stripe)
  • Pin 4: Dimmer (light blue/red stripe)
  • Pin 5: Power (light green/yellow stripe)
  • Pin 6: Fuel Flow Input (light blue/pink stripe)
  • Pin 7: Ground (black)
  • Pin 8: Speed Input (dark green/white stripe)
  • Pin 9: Ground (black)

NOTE 1: Wire colors may differ slightly from year to year.
NOTE 2: Pin 7 and Pin 9 may or may not be connected together at the factory.



Once you acquired a junkyard Tripminder, it would be wise to test it outside the car to verify it works. Hook up power, ground, and ignition. If the unit works you will see ?12:00 RESET? on the display. Try the buttons. If some or all of the buttons don’t work, do not worry.

This is how you fix the buttons: take apart the computer (when turned off, in a static electricity-free area) and clean the metal contacts of the buttons with the sandpaper. The Tripminder comes apart pretty quickly. A flathead screwdriver inserted into the four slots on the sides will separate the case into a front and a back side. Pull the back from the front and unfold the computer’s circuit boards. It unfolds like an accordion.

The last board is bolted to the front of the Tripminder via four 4mm bolts. Unbolt these and pull the circuit board free of the Tripminder. You will now see the other side of the circuit board: seven little push buttons (metal, not the plastic ones) that surround the vacuum fluorescent display of the Tripminder. Fold a small piece of the sand paper (sand on both the top and bottom) and GENTLY slide it between each of the seven buttons. You should be sliding the paper between the metal you see and the circuit board. Push down on the button and move the sandpaper up and down a few times. This will clean both sides and remove all corrosion/oxidation from the contacts. When this is done blow off any sand or residue with compressed air. Reverse the disassembly process.

Now take a look at the standard (what is currently in your car) digital clock’s wiring. When you compare this to the Tripminder you will see that you already have 4 of the 7 wires needed for the Tripminder:

  • Pin 1: Ground (black)
  • Pin 2: Power (light green/yellow stripe)
  • Pin 3: Ignition (light blue/pink)
  • Pin 4: Dimmer (brown)

NOTE: Wire colors may differ slightly from year to year.

You will need to remove the wires from your car’s clock harness and splice them into the Tripminder’s harness. Your brown wire (pin 4) goes to the Tripminder’s brown wire (pin 4). Your black wire (pin 1) goes to the Tripminder’s black (pin 9) wire. Your light blue/pink wire (pin 3) goes to the Tripminder’s wire in pin 3 (colors may vary). Lastly, your light green/yellow wire (pin 2) goes to the Tripminder’s light green/yellow (pin 5).

There are only two extra wires needed: all the others are there with the factory clock. One is for the fuel flow, which you will have to splice from PIN #34 at the EEC-IV engine computer. The other is the input wire for the speedometer.

For the speed input, you will have to remove the gauge cluster and disconnect its wiring harness. This is where the Ford EVTM manual will come in handy. Directly from the EVTM, the signal you want is located in circuit #150, a dark green/white stripe wire. The analog performance cluster (XR7 models) has the speed input at PIN #18. The regular cluster has it at PIN#3. Double check all wires and circuits to see if you are getting a pure speed signal from the engine computer. There may even be two dark green/white striped wires feeding it. Your car may vary from this. Once you are sure you have found the right circuit, use a tap splice and connect a length of wire to this circuit. Run the wire back to the Tripminder and connect it to PIN #8 on the Tripminder. You now have speed information to your computer.

The fuel flow input works on the same principle. Just about all Ford products using EEC-IV computers have a fuel flow signal that comes from pin #34 of the EEC computer. Anyone that has done the mass air conversion should have no problem getting the signal either. Just remove the passenger side kick panel, slide out the computer and look for pin #34 and a light blue/pink striped wire coming from it. Use the tap splice again and connect this wire to the Tripminder’s pin #6. Route the wire between the glove box and the blower motor. We suggest using a very long wire and tucking the extra length away, just in case you have to replace the blower and need that wire out of your way.

Now reconnect the battery, turn the key, and that’s it! In a matter of hours you have now given your car a neat little toy that almost no one else has. Many cars costing $30,000 or more today do not give you the information this Tripminder will. More importantly, it will look factory.

Rotary Heater Panel Conversion

The stock 1985-88 Cougar stock (non-ATC) heater panel tends to be a little too low and inconvenient to use. And it’s even worse if you have a floor shifter. There is a slicker, better solution: a conversion to the newer-style rotary panel. Not only will this make your car’s heater panel much more functional, but it just screams “custom” and will get you noticed at car shows. By the way, you can also do this to a 1980-84 car as well; it’ll just have to go back in the stock location as that dash is a little less forgiving.


Rotary Heater Panel Conversion

Now if you have the storage bin above the radio, you’re all set. You’ll have to give it up as this is where the new panel will go. If you have the factory EQ and want to continue using it, or just want to keep things as-is, then you’ll have to put the new panel back in the stock location.


Parts Needed

Essentially this is all you need to do the job:

  • The new panel
  • Cable for the new panel
  • All related wiring harness ends, nuts, and bolts
  • New rear defroster switch (if your car has that option)
  • Wiring diagram (very helpful!)



First, remove the old panel and slider cable assembly. Then, you’ll need to do a little repinning of the wires for the new panel (not too much, believe it or not), install the new cable, push all the harnesses in, and bolt it up where the storage bin was. You also will have to cut the vacuum lines going to the old panel and using vacuum tees, splice in the new one. The most amazing part about this job is that even if you’ve never done this, it’s a very logical and enjoyable project, and one that’s not too confusing either. When you’re done, you’ll look at it and wonder why it never came like that from the factory.

Before you start it’s highly recommended that you read these tips (special thanks to Adam):

  • 1990-91 Taurus/Sable climate controls will definitely work. After that, it’s unclear because at some point between 1992-95, Ford switched to a motorized heater door controller. The panel looks identical from the outside, but the temperature knob has an electrical connection instead of the cable linkage. Also, some later Mustang and F-150 panels use a pulley-style cable instead of a straight cable, like our cars have from the factory. At this time it’s unknown if the pulley-type cable system can be installed in our cars. Be sure to double check the year of the car and the style of panel before you do this installation.
  • We’d recommend picking up a few extra blower switch wiring connectors from the junkyard as they are rather brittle.
  • The red harness may have some wiring color discrepancies. The Taurus may have a purple/green wire that interchanges with the solid purple wire on your Cougar. And the Taurus may have a light green stripe that’s yellow on your car. Wiring color specs are not set in stone!
  • The 2-wire lighting harness does NOT have compatible prongs, so you can’t swap the pins into the new connector like you can with the other harnesses. You can simply tape up the old plug and use tap connectors to connect the new plug.
  • If you’re planning to put the rotary panel in the stock heater panel location there is some slight tweaking that needs to be done. A usual solution is to cut off the guide pins on the back of the new panel, drill new holes in the mounting area, and use clips to keep the panel in. You may also need to space out the panel with nuts or washers. Remember, this isn’t an exact science and mods will need to be made in order to retrofit this panel in your dash.
  • The Cougar/Thunderbird defroster switch has four wires, not five. It is missing the dash illumination wire. That wire is light blue/red and you can tap into the stereo wiring harness to get it.

For an in-depth, step-by-step instruction manual on how to convert your car to the rotary heater panel, download the PDF file here.

Console Installation


If you’re not one of the lucky ones that had a factory console in your 1985-88 Cougar, don’t sweat it. Installing a console one of the easiest installs you can do to your interior. However, you do have some challenges ahead of you, as finding a console is tougher due to the age of these cars. The salvage yards are getting picked clean of hot-item parts like consoles, and yards are crushing older cars at a much higher rate due. Plus people can be ignorant and totally break the console parts while trying to get to something else.

Still, that shouldn’t deter you from wanting to put one in. If you’re shopping for one, you can get the donor console and all related parts (panels, metal brackets, etc.) from these cars:

  • 1985-88 XR7 (all)
  • 1985-88 Thunderbird Turbo Coupe (all)
  • 1987-88 Thunderbird Sport V8 (all)
  • Optioned base and LS Cougars
  • Optioned base and LX Thunderbirds

While you can theoretically use a 1983-84 Cougar/Thunderbird console in a 1985-88 car, it doesn’t quite line up at the dashboard perfectly, although it could possibly be made to work with some trimming. No other Fox chassis console is a direct fit in our cars. Seems that just like floor shifters, Ford made sure that each Fox car had its own console.

Here is a complete shopping list of all parts needed:

  • Console itself
  • Back metal support bracket
  • Middle metal support bracket
  • Dash metal support bracket
  • Lighter panel
  • Storage tray (see below)
  • Switch panel
  • Console liner
  • Console lid and hinge
  • Console wiring (*NOTE: this should be attached to the underside of the console)
  • Wiring for the light (green/yellow and black wires)
  • Radio panel bezel for a console car
  • All related screws and bolts

Not only is finding a console sometimes a hassle, but finding one in the color you need can be even worse. Good news is, it can easily be painted using interior spray paint.

Then there’s the problem of the console lid. It’s not a secret about these cars that the latches on the lid break easily (and likewise, the console liner latch area). That’s what happens when people just let the lid slam shut, instead of gently pushing the lid down, or better yet, pushing the button on the latch in while closing then letting go. There are no more replacement parts for the latch or liner either. So finding a good latch and liner is a challenge; you may need to get them from several different cars to mix-and-match yourself all the good parts.


Console Lids

There were two different style console lids used from 1983 through 1988 and fortunately you can use either style on your new console. The earlier one (1983-84 for sure, sometimes later) is taller and padded, usually colored, with a pronounced indented line down the middle. The latch button is located on the front edge, hidden from top view.

The later lid (1985-88) is usually charcoal grey in color and is much flatter. There is no padding on it, and it’s covered in leather. The latch is on the top.

From the factory Ford seemed to have no rhyme or reason in using either lid. Some people have reported the earlier lid in brand-new 1987 cars, while others have said their lid was flat on their ’85. Basically it’s potluck as to which one you’ll find, and one is not really more “correct” than the other. Be aware that the latch parts do not interchange between the two styles.



Console Lid

Console Lid

A view of both lids in a side profile. The first photo shows the later (1985-88) thin console lid, while the second photo shows the earlier (1983-84) taller console lid. Most people seem to prefer the taller lid due to the padding and the variety of colors. If you find a taller lid that is cracked, it is possible to buy a console lid cover in plastic that can be painted to match (see below).


Console Lid Cover

If your padded (thicker) console lid is cracked, you can buy an overlay from vendors such as and Accu-Form Plastics Inc., as well as on eBay. The overlay can be painted to match or contrast your interior, and simply applies using double-stick tap on the underside. It’s a slick, efficient way to save a console lid while beautifying and protecting it.


Console Tray

Console Tray

Another area of note is the storage tray. For all cars without a floor shifter, the area between the switch panel and the console had a storage tray with a rubber liner. This is great for putting your drink, cell phone, music player, or your change. Some cars had a separator in the middle (top), while others had a completely flat open area (bottom). If you have the column shifter and are planning on keeping your car that way, you’ll need a storage tray for your console. Floor shifters had their own unique cover (different for automatic and manual cars). Also, you really cannot use a 1983-84 tray as the angles are too different to fit a 1985-88 dash.

One important part to find is the correct console switch panel. This is where your factory window, seat and mirror switches will go. Bad news is, there were about 8 different configurations of these panels between 1985-88. Good news is, the most popular configuration (power mirror, power windows, and power driver’s seat switch) is going to be easier to find. Plus you can easily make your own switch if need be, out of thin aluminum. But with any luck you’ll find the one you need without too much hassle.

Last, you will have to figure out what you want to do with your seats. Sometimes people upgrade to bucket seats at the same time as the console install, and that makes things a lot easier. But if you really like your current seats, you have two options:

1. You can use a reciprocating saw and cut off the factory consolette from the driver’s seat. Yes, the consolette is welded onto the driver’s seat frame. Cutting it off will make sort of a bucket seat for you. You’ll have to sew the material together where the consolette was. It’s not a perfect solution but it works fine, and you’ll most likely never see it anyway. Of course, you can always have an upholstery shop sew in a new piece if you wish.

2. You can find a similar seat bottom and transfer your material over. Since all Mustangs had consoles, we’ve discovered that 4-cylinder Mustang LX seats are perfect donors. Their seat bottoms are the same dimensions as our consolette seats. Simply remove the seat bottom (frame and material) from the Mustang seat and yours, swap material, and replace. No cutting of anything is necessary. You will still have the same material imperfection as mentioned above, so you’ll have to do some sewing. Of course, if the Mustang seat fabric is a different color than that used in your car, it’s not going to look all that great, so shop wisely.


Once you have all your parts, here’s how to install them.


Console Installation

Begin by removing the consolette switch panel. Unscrew all of your switches from the underside, and save the screws—you’ll reuse them later.


Console Installation

It also helps immensely to remove the seats now. The factory used a combination of bolts and nuts to hold the seats down. You will use 13mm, 15mm and 18mm sockets to remove them.


Console Installation

Before you go yanking the seat out without discretion, be aware that you have to disconnect all harnesses under the power seat. In particular, this brown one (refer to arrow) is the power seat harness. If you have power lumbar or power recline, those will have harnesses too.


Console Installation

This is what the car should now look like. You can also remove the radio trim panel at this point.


Console Installation

Next is the removal of the factory sliding ash tray. You’ll be losing it in favor of a fixed lighter panel and separate ash tray on the console. Pop out the ash tray and using a screwdriver, push down on the retaining tab as shown here.


Console Installation

The ash tray simply slides all the way out of its housing. There are 4 ball bearings that might also pop out at this point. You will need to reach under and disconnect the wiring for the lighter.


Console Installation

Next, take out the ash tray retainer housing by removing these screws. The housing will then completely slide out.


Console Installation

Time for a test fit of the console. Place the console in the approximate area and let it sit for a moment.


Console Installation

Pay particular attention to the alignment of the console to the dash. The tips of the console should be flush with the back edge of the dash, as shown here. From here on in, it’s got to be this way or your alignment will be way off.


Console Installation

Install the dash-to-console metal bracket. It will serve as an alignment gauge from here on in.


Console Installation

Next up is cutting the carpeting…but you have to know where to cut first. Bolt the rear metal support bracket to the console as shown. This isn’t permanent; you’re just going to use it to mark the carpeting for the cut.


Console Installation

Do the same for the middle metal support bracket. Now simply trace around the brackets (all four sides) with a permanent marker or grease pencil. Trace as close to the brackets as possible. If your carpeting is dark colored then you might have to get creative.


Console Installation

Once the marks are made…


Console Installation

…remove the console and make the cuts. Be aware that it’s okay to miss on the cut front-to-back. But side-to-side, if you take too much carpeting out, it will show when the console is in. Precision is very important here.


Console Installation

WARNING: Be EXTREMELY careful on the front cut. There is a main wiring harness directly underneath the carpeting in this area. Use scissors or pull the carpeting up before making this cut.


Console Installation

This is what the floor should look like when you’re all through cutting. The left side of the picture faces the front of the car.


Console Installation

Put the console in place again, with the brackets still attached. The rear bracket will have no interference. Up in the middle, though, you will have to make sure all the wiring is out of the way. There should be a hole in the floorpan’s raised section that will accept the tang from the bracket. This lets you know you’re in the right place.


Console Installation

Now you get to attach the brackets to the floor. Using a 1/8″ (or slightly smaller) drill bit, drill out holes in the floorpan at the spots indicated. Then screw the brackets to the floor. When this is done, remove the screws at the top of the brackets (on the console), but leave the console in place.


Console Installation

All the hard work is now pretty much done. You can begin assembly by attaching the console wiring harness to the factory harness coming through the carpeting. Also, you can drop the console liner in and wire the light switch to the bulb, and place the bulb inside the holder on the liner. Then bolt the lid’s hinge to the console; note that the holes go through the rear support bracket. When done, put the screws in the console liner (and don’t forget the three screws in the bottom).


Console Installation

Then you can attach your switches to the console switch panel. Bolt the top of the middle support bracket to the console, then fully attach the switch panel to the console. You should be able to close the console lid fully at this point. Note also how rock-solid the console is with the brackets attached. Now it’s just a matter of the small details (storage tray, lighter panel, radio panel, seat reinstallation, etc.) and before you know it, you’re all finished. Hook up the battery, test everything out, and enjoy the new console!