UNKNOWN_SS

Hey guys, I still have my ls1 in my car and looking to swap in this ls3/t56 combo that I got hooked up with, it's the complete engine and trans with ecu and all harnesses .. question is, what is exactly that I need to drop the ls3 in and for it to be ready to go? Thanks in advance.

Kamaro

You can keep your existing LS1 ecu and just use an LPE adaptor box to switch from 58x to 24x. I think this is the simplest way to drop in a LS3 engine in your car. You can always sell the LS3 ecu and harness for much more what the LPE adaptor would cost.