LS1 engine harness

[mightymouse713]

I ended up buying this one on another forum:

this is a ls1 conversion harness done by speartech
they installed a fuse box,inside diag port,and check engine light,also instaled the fuel pump relay
i am taking it out now but here are some pics of it as it comes out 450.00 shiped it is for a auto car also have 2 pcms for sale.

I bought it even though I have an M6 setup, he said it can be used as a stand alone. I bought both pcms and the harness shipped for the price stated. It sounded to good to pass up since it was redone by speartech. I have seen just the harnesses for 250+ and would need mods so it seemed worthwhile. Can anyone give me input as to using this on my LS1/T56 setup?

[mightymouse713]

I am curious to what differences there are on the wiring harness of a 98 to a 99+. Are there differences I will be dealing with since I am using a 98 PCM/harness on a 99 LS1 engine? The harness was modded by speartech and PCM flashed for 98 setup.