Originally Posted by ScOoTeR
I think he was getting at the fact that the wiring takes skill - and not everyone can do it right the first, second or seven hundredth time. It's easy to see where he's coming from: wiring mods to put a gen I SBC in a jeep is far less of a challenge than a gen IV.
Hell, look at the trouble Becky had - and that was with someone experienced with the wiring and calibration of LS swaps...
Becky's problems were not with her engine. They were a result of a transmission that was several years older than the engine. The OP is asking about an engine swap and says nothing about the trans. If he's going to gut the old ECM in favor of the new engine, there are wiring issues regardless. I stand by what I said. Jim's Performance took my old harness, stripped everything I didn't need and rewrapped it. Everything was labeled and all I had to do was plug it in. There were a half dozen or so hookups that didn't plug back into the engine itself. Always hot, keyed hot, O2 sensors, (yes, you have to weld in bungs), fuel pump (which he may need anyway) and a couple others.
To me, it's not much different.