I've got this in engine swaps too, but in an effort to cover all my bases here goes...

I have a 87 camaro that had the 2.8 v6, swapped in a 350 tpi from an 89 firebird, used the donor cars engine wiring harness, got a new computer, etc. The engine cranks, but now I am unable to get 12v to the fuel pump, so, after some wire chasing and head scratching I think "maybe you have to switch out the interior harness too" since the c100 (1000?) connector on the firewall is different for the v6 and the v8. And, since my v6 one was a missing a pin at the fuel pump spot I figured this would solve my problem. So today I go to swap out my interior v6 harness with the v8 one from the donor car. However, upon closer inspection the interior harness for the v8 is junk! so now I'm stumped, heres what I'm wondering...

1. Am I correct that the v6 interior harness needs to go?
2. Is there any way to make the v6 interior harness compatible with the v8 engine harness?
3. Since my v8 interior harness is junk, what do I do now?!
4. If I get a new interior harness can I get an 89 iroc (for example) or does it have to match the engine wiring exactly (ie I'd need to find a 89 formula harness)??

Thank you guys for any help/advice you may have. I'm so close to getting this car on the road and this wiring stuff is driving me crazy!