iam starting a lt1 swap in my 88 iroc camaro and iam geeting the a 93 lt1 with wiring harness and computer for 650 if i have the computer that goes to the engine do i have to worry about the vats and do i need to tar out all the wires under the dash or does it just plug in right there at the driver side firewall because that where i unpluged my old wiring harness and my last question is will the new wiring just plug right into the head lights

The headlights are not PCM related so those should be left alone on your car. The 4th gen PCM will not plug into the same wiring harness as the 3rd gen stuff. The easiest way IMO to deal with the VATS issue is to have it programmed out of the PCM. However, if you want to keep it provided your car did have it, do a search and I believe you'll find a thread regarding this very issue. Most of the wires you'll need are there at the bulk head connector on the drivers side. Check the sticky above.

can anyone explain a little better on my questions and the head lights do contect to the whole wiring harness

The headlight stuff is at the bulk head connector also. There is no need to disconnect the entire connector. Chop out what you don't need. There are 2 looms from this connector...at least there were on my 87 Trans Am. One side handles the lighting and the other, the engine managment. I take it you're planning on splicing both harnesses together? If so, you'll need to keep the original lighting from the 3rd gen. I never removed the whole harness. I took the loom off and worked from there. If I'm not clear enough, maybe one of the other guys can help you a little better.

thanks that helped a little bit better