Been There, Done That
I have done this swap before. I swapped an '88 TC powertrain (Engine, Trans, Rearend) into an '85 4 cyl 4speed. It wasn't that difficult, really. I used a fuel tank and pump from a '91 GT, used the Turbocoupe's nylon/seel fuel lines. Although they are longer, you can route them so that they work and still look good, it's just a PITA not kink them in the process. The wiring, ahh, what fun. First off, i grabbed COMPLETE wiring diagrams for both cars. Found out what needed power on the TC's ECU harness and grafted it into the '85 harness, using O.E. style connectors. Looking under the hood, it's like the car was that way from the factory. If you use a harness from an '87 and up mustang, then you run into a problem with wiring up the guages, as they are different. Basically, either way you go you are going to have to graft two wiring harnesses together, no matter which way you go. But it's so EASY, just get COMPLETE wiring diagrams for the two years of vehicles you have and go to town, splice + to +, switched power to switched power, ect. easy, and everything will still be fuly functional. you can purchase them here, and have access for 1 year. \
http://www.alldatadiy.com
I used the TC's fan assembly, and had the "nostrils" from the TC's hood grafted into the Mustang's hood so that the intecooler was functional, I would post a pic but i'm not on my home pc right now. The only other problem I ran into was the fuel guage not working. Ford changed the resistance of the sending units in 1987, so since we are using a '91 tank, the fuel guage in the dash of the '85 reads awkward. I can fix it by adding a resistor in the circuit to the fuel guage, but haven't had time.
With the TC motor in the '85, with fuel pressure at 55 PSI, and boost turned to 18 PSI, the car cranked out
[email protected] last time out, this is before the intercooler was functional, other then the boost controller and fuel pressure regulator, the TC motor is completely stock with 158,197 miles on the clock.
The whole process took about 5 days working 8 hour days with 2 people working on it.
