I have a speartech 58x harness, and I want to preparing my 84 trans am stock wiring to connect to the new harness / ECM. I've been reading through the threads on how to do this. My question is:

-Do I modify the stock dash harness for this? After lots of reading, I'm realizing that the stock engine harness and dash harness are not the same.

-How do I remove the dash harness? Do I have to pull the dash apart to get to the tachometer connection?

Sorry if this sounds stupid.

 

All the wires are either on the C100, C207 or accessible under the dash near the C207. With the exception of the wires for the starter relay which are by the pedals. Read through the wiring threads in the stickies especially the last "extra swap info" one.

 

^ That

The 3rd gen prep thread shows how to strip the old engine harness down to essentials and additional info thread shows where each goes based on year