I've done the 4 banger to 5.0 swap. I'd take all of the underhood wiring, but remove it after you get the engine out. Take pictures of where everything was located at, this will help later. Take the headlight wiring just because you might need it for the alternator. I believe the alt wiring is different for the pre 1990 alternators. The dash wiring is the same for the 2.3 to the 5.0 except for air bag cars. Also, vacuum lines and trees would be a good idea to collect as well, I didn't do this and had to fabricate some things on my own. There is a second vacuum reserve behind the passenger side fender as well that is not on the 2.3. Hope this helps, and have fun.