I have an 01 vortec 350 in mine, I used the harness from the same vehicle. For me to get it to run without doing anything to the computer I had to use the keyed ignition and keep the body control module. I run only the oxy sensors in the manifold and it runs fine but the cel comes on.
96' and 97' don't have passlock theft system, although you can reprogram the computer and remove passlock for ~$200. Same process as TBI. I used a 99' wiring harness and bought a 97' computer. Buy a FSM for the year computer you are using, the pinout locations move around by year. It is time consuming, especially if you haven't done one before but nothing particularly difficult about it.