I'm doing a L99 6l80 swap into a 1987 IROC,

my question is do I need to purchase standalone harness and ecm or can? do I use the OEM harness that came with the engine and transmission? the harness came with the OEM fuse box out of the 2010-15 Camaro SS.

 

This probably doesn't answer your question ,but . I went with PSI harness.. i have a ls3 - 6.8 out of a 2014 Camaro and i kept the computer and just used there harness it comes with a fuse box.

 

You can use either. The OEM harness will have a bunch of other stuff along with it that you likely won't need. You will still want to trace it all out and depin anything you don't need. Take a look at the LS wiring stickies at the top of the LS/LT swap forum and the same ideas apply to any LS harness. If money is no issue, it may be easier to go aftermarket as suggested above.

 

this statement shows this might be way over your head.

 

Thanks for absolutely nothing. People are not allowed to come here and ask questions? I'm supposed to know the answers before I ask them.

 

Thanks, looks like after market will be the way for me to go.

 

Take some time to read through the DIY wiring threads. They will help you explore all the options you have and then a plan will resonante with you. There isn't a right or wrong way to tackle this. Skill, budget, and time all come into play which only you can answer. Reading through the various topics dedicated to this topic will help steer you.

 

It often is but there is something to be said retro fitting an OEM harness. The knowledge and skill gained doing so will only help you with the rest of the swap. However, should you decide aftermarket (many of us have gone this route), the OEM harness has value and can be sold for some decent coin.

 

Thanks for the info, I'm not new to swapping motors or building vehicles however, they all have been older and never an LS swap requiring all this electronic stuff. I'm totally capable of retro fitting the harness just never have attempted anything like this. I'm going to read through the DIY on the forum and may give it a try.

 

Its really no different than any other swap. In ways the LS wiring is simplier than an older TPI setup. All closed loop fuel injection systems operate similarly.