Anyone done an engine-side wire harness? How difficult?

The harness is about $150....yearone
I'm about to plug mine in today or tomorrow. ...in a 'Cuda

Pretty hard to screw it up...but I'm sure I'll be here asking at least a couple questions!

I think the "hardest" part will be connecting the wires to the starter...past my headers, upside down on my back...ugh. Whatever, it's gotta be done!

Jeff