96 GT with 02 PI motor. Retained AC compressor (just charged) - fuel rails - and modified the brackets for the coil packs and ran the wires. Also had to use part of the same wiring harness that was in the car from factory. I never converted to COP because I hear that I would run into problems. So not to take any chances, retained most of the wiring harness. Been 3 years and no problems.
Basiclly, 1/2 of the wiring harness is retained. I updated the wiring from the starter to the battery. The main harness is in 2 sections. 1 for the engine electronics (coils paks - sensors - fuel injectors - ect) and the other is the main harness for the starter.
Since I basiclly just swapped out motors and sensors - the car has yet to be tuned. It is on the list but the car is acting normal and I havn't had any issues to date as far as running poorly.
Here is a pic of what it looks like ..............
Because I used the 02 pulley system, I had to modify the bracket that holds that coils pak on the passengers side ...........
And the only issue I had with sensors was that 1 sensor does not have a port in the PI intake. 1 sends a signal to the computer and the other sends a signal to the dash gauge. Also, the Low Oil sensor that was plugged into my old oil pan was cut and not used on the new motor. Thankfully - this did not trip low oil light on my dash. Pic of other sensor for temp .............
All in all, took me and a few friends the weekend to do. I also did other stuff like change out the tranny and do some suspension work. Also added headers and changed the exhaust completey.