Hello I’m new to this group. I have a 1992 RS 25th anniversary with a 305 TBI with a T5 5 speed. I am doing a 350 LT1 swap from a 1995 firebird. Can I use the stock harness from the 305 that’s in the car now? The motor should make about 550whp when done I have a P1S procharger for it. Don’t really want to go aftermarket ECU like Holley ECU as the pockets aren’t that deep. Thank you. Of if you guys know another stock harness replacement any from from the 5-$700 range if the stock harness cannot be used.

 

Nope. Too many differences in sensors, and number of fuel injectors.

 

Plus you have the optispark on the LT1 vs. HEI on the current engine.

Probably better to get an actual LT1 harness to do the swap.

 

Initial thoughts was to the subject, TPI it can be done but after reading the body of the message, LT1 any thing is possible. The LT1 PCM connectors are different as well and that would be a boat load of splices to switch it over not to mention adding the extra wires for the ones absent from the TBI harness.

 

I would suggest purchasing a used LT1 (Gen-II SBC) Engine Harness (from a Camaro or Firebird) from EBAY.

It will work in conjunction with some of the Original wiring, but mostly from the C100 Connector.