Ls1 engine harness questions auto or manual
 

I was wondering if there was any difference between the engine harness on an ls1 is any different between the auto and manual. I'm going to assume yes.

The reason I ask is that I browsing for a motor and I'm finding a lot of auto cars. I'm sure I can use the engine and swap over to manual flywheel and clutch. But I was wondering if needed to look for another harness if I went this route. Or can I just gut the auto stuff out and use it on the manual, I can't imagine there is a whole lot to hook up on a t56.

Also, does this apply to the engine computer. Or can the auto stuff be programmed out?

Guys swap from manual to auto or auto to manual in F bodies all the time and it's no big deal. I'm sure the harness is different but it wouldn't matter because the auto trans plugs would just not get used. You already don't use the reverse lock out plug. So the only thing the T56 needs for wiring is the VSS and back up lights and bet the plugs are the same for both T56 and auto on those.

Yes the computer needs to be changed but you have to change that anyway to get your speedo right and remove the VATS so it would not be an added cost to remove whatever auto trans stuff might be going on. One note on the computer not sure if I told you this but the 98s are crappy computers with the much slower LT1 baud rate in them. A lot of tuners won't work on them even for the simple stuff you need changed.

The bigger issue I see is all the stuff you don't get with an auto car that you need. Like the T56, bell housing, etc. That's a couple grand worth of stuff that selling the auto would probably not cover.

I appreciate the input, your the best! For now I'm just trying to assimilate as much useful information as I can. So when the time comes I can make a more informed decision. I remember you mentioned the higher horsepower of the later engine, but the computer issue is new.

As always thank!

I can only speak to the Painless harness that I used but here is my $.02
The harness had a section to cut and tape out of the way if you were not using an auto. Also you need the plug for the skip shift solenoid even if you are disabling it in the computer as it is also used as the reverse lock out (5th gear is very close to it and I have heard horror stories of folks jamming into reverse instead of 5th). Yes, I also recommend upping to at least the 99 computer. The processing speed is much faster allowing better fuel table acquisition.