If I go with a 88 5.0 bird/cougar harness, how much of a wiring nightmare am I looking at? I tried searching but couldn't find anything.
Its really not that bad when using the 88 harness. There are a few pins on the black and grey connectors that get moved around and a couple tha you have to splice. Then there is the fuel pump wiring which really isn't bad either. I have an 87 tc that I swapped using the 88 harness.
I did the same swap, all of the information is in the search function here. I used an 88 harness and also the 88 fuel pump wiring from a V8 car.
http://www.foxtbirdcougarforums.com/showthread.php?1218-turbocoupe-5.0-swap
finally found this (with a google search). says just match the wires color-color. is this true?
that is what I did, and everything works. I havent started on the A/C system yet and I expect to have some issues there but nothing that wont be too hard to figure out.
I'm not worried about a/c. Out of the 30+ vehicle I have owned since I turned 16 (only 25, i like to change em up quite often lol) only 2 have had functional a/c.
Still debating on going with EFI or carb.
Efi is easier than you think.
do I need the 5.0 headlight harness as well or just the engine harness?
Just the engine harness. lights come from a different set of wires on the drivers side.
you will need to run wires for your alternator since it will now be on the passenger side.
that's no biggie. I have a 190amp 3g that I will be using anyways. I don't like ford's tiny alternator wiring anyways