1987 cougar 5.0 swap into 1983 5.0 thunderbird

October 01, 2014, 09:30:29 PM

Hello, I'm new to this but here it goes, I currently have a 83 tbird with a problematic 5.0 and I'm considering putting in the drivetrain from a low mileage 1987 cougar that I found (cougar was t-boned) I'm wondering how difficult this will be and what electrical issues I would come across

:eek::eek:

1987 cougar 5.0 swap into 1983 5.0 thunderbird

Reply #1 – October 01, 2014, 11:18:30 PM

Swap a 5.0 h.o. from a mustang. Might as well upgrade. Coolcats has a basic write up.

1987 cougar 5.0 swap into 1983 5.0 thunderbird

Reply #2 – October 02, 2014, 09:00:45 AM

The wiring harness on the two will be very different with regards to the fact that your current car is a CFI car (throttle body with two injectors in the middle of it) and the 87 car has sequential injection like the Mustangs. The general consensus is that you cannot use a Fox Mustang EEC harness on one of our cars however that is another debate. If you want to pursue this then you will need to strip the EEC harness out of the Cougar and get wiring diagrams for your Thunderbird (I have them for this car) and the Cougar to see what you are going to have to do to make it work electrically. You could opt to just use the long block out of the Cougar and keep the CFI but why shoot yourself in the foot? If you have the time and the willingness to do the swap you can make it happen and the benefits are numerous over the antiquated CFI system.

One thing you need to realize is that the '83 cars have a lift pump in the tank and then a high pressure pump on the rear frame rail. The '87 Cougar just has a high pressure pump in the tank so you will need to swap over to this system which also has a return. No hard but you need to be aware of it.

You will also need to ditch the stock exhaust and put duals on the car as you will not see much of a gain hp wise with the py single system you have on the car. A search will turn up tons of info on this.

As Haystack pointed out an HO swap would be the thing to do at the same time. You do not need a Mustang engine to do this so do a search on here as there are several threads on it.

Darren