i heard painless is still working on a harness for this swap. although i think the cost is up there and you have to either get your computer flashed or swap for one of theirs. i know its like others but the 5.0L is much cheaper and has a huge support group. im running one in my 64 galaxie, 46 ford and putting one in my 51 mercury project. good luck with it.
I widened the body 3", and channeled the car a bit. The car has simple straight rails. Now matching fenders to the frame is a different story ...
The Detail Zone makes a harness for the engine and trans. It's a bit of a hassle to use the factory stuff but it can be done. i built a 49 Merc with EVERYTHING from a 95 Mark 8 and it was weeks of wiring.