need help,transplanting 89 5.0 into my 95 v6

[mustang_man1995]

i have a 1995 v6 automatic, i bought a high hp motor and 5 spd trans from a 1989 mustang. i have the complete engine harness and computer out of the 89. what would be the best and easiest way to do the swap?? i was thinking about using a painless wiring kit, but i was told that if i found a harness and computer from a 94 or 95 gt, that it would be much easier. but i was told by another person that i would need to change something with the distributor and the fuel rail!! please, i need all the help you guys can give me. i'm trying to get the car ready for the spring, and i'm confused!!!