camarozz383

iTrader: (3)

can someone tell me what in gods name I have to do with my wiring harness to make it work, I have ls3 style coils and ls1/ls6 wiring harness, will just plugging in the harness work? also do they need to be plugged in a certain order? or do I need another harness? I am using a MSD 6012 ignition box and harness, the engine is a 5.3 from a 2008 gmc pick-up.thanks

LLLosingit

iTrader: (4)

I could be wrong but I think you'll need the harness for the gen 4 engine. I'm pretty sure you're going to run into other issues using a gen 3 harness on a gen 4 engine since some sensors are in different locations on the Gen 4.

•LS2/LS7 Cam sensor in front. Gray crank sensor connector.
•LS1/LS6 Cam sensor in rear. Black crank sensor connector.

camarozz383

iTrader: (3)

I got the proper harness for the engine sensors, only problem I have is the coil harness I think? here is what I'm talking about

LLLosingit

iTrader: (4)

I'm confused You said in your first post " I have ls3 style coils and ls1/ls6 wiring harness"
LS1/LS6 is 3rd gen and the LS3 and your 2008 5.3 is 4th gen.
Yet you say you have the proper harness? The harness you should need is not for an 3rd gen LS1/LS6 (MSD Ignition#121-8886) I think you need a harness for a 4th gen. (MSD Ignition 88862)