I've finally decided to get started on the wiring for my LT1 swap. Problem is, I don't even know where to begin. I have all of the things I need for the swap (I think), and I don't have the full underhood harness, just the engine harness. I've got all of the diagrams of my car and of most of the engine harness connectors for the LT1, but I don't really understand where to go from there. Am I supposed to match up the wires from the bulkhead connector to the connectors on my thirdgen? Which wires on my harness will I not need at all? Someone is probably going to tell me to search, but I've been reading through all of this stuff for about a month now and am still pretty stuck.

 

You are pretty much going to have to re route the wires from each of the connectors on the LT1 harness to either the bulkhead connector at the firewall on the drivers side, main ones here are going to be the oil pressure gauge sender, tach signal, coolant signal, brake switch signal if auto, probably a few others, then some of them are going to the clear connector under the dash on the passenger side, injector power, ecm/pcm power, aldl port wires, VSS signal will either go to it if V6 / TPI, or one of the brown wires going to the buffer box if its a TBI car, vats if you have the 4th gen vats box to use. Hopefully this gets you started a bit, for each of the harnesses i build i spend probably 10 or so hours, maybe a bit more, if you might be interested in just sending what you have and receiving a complete one back PM me. Or if you need more help beyond this feel free to ask, PM or email.