Quote Originally Posted by TTU713 View Post
I plan on doing a 4.3L to 5.7L LS1

What I seem to not understand about the swaps (looking through a few here) is the gauges. How does the stock cluster work if you were to order an aftermarket wiring harness? For example, I have an EFI CONNECTION wiring harness from my last v8 swap, all the harness did was control the engine/trans (it had it's own pcm, did not come with wiring for any emissions/rear o2s) which meant I was not able to use any gauges unless they were aftermarket

My guess is that I will HAVE to buy a stock 5.3L engine harness/pcm and have it flashed somewhat to work with the LS1. Which would seem to also allow the stock gauge cluster in the Silverado to work. So buying a full 5.3L harness and replacing the 4.6L harness with it, would pretty much allow me to throw the ls1 in there and plug everything up and be 100% ready to go


also, seems a lot of people on the site refer to an LS1 as the 5.7 AND 5.3L, it is somewhat confusing - but can I consider the 2 EXACTLY the same as far as major parts (like wiring/mounting)
We usually refer to the swap as an LS swap regardless of motor. They are the LS series, based off the LS1. 4.8, 5.3, 5.7, 6.0, and 6.2 are all LS motors. The swaps are the exact same other than the intake and TB.