Blue89Bird

What has to be changed out in order to run a standard SBC in a 4th gen and still have all of the guages work properly.

Is the best thing to do removal of the existing wiring harness/ecm and go with a standard painless wiring harness, or can the existing harness be modded to work.

What about the ABS system, is it able to be retained with a carbed SBC and a standalone harness without a ECM.

WS Sick

The ABS has its own complete system on board, so it can be left in place. You can reuse the starter, water temp,alternator, oil pressure,oil level,water level, etc, but some of the AC wiring goes through the ECM. All this stuff rides the same harness into the firewall as well so you'll have to label and cut the ECMs wiresthat go through the firewall. (if you do away with it.)

The electric fuel pump will have too high of a pressure for a car, so you'll need to get a carbed type elec fuel pump and regulator, and it would be best if you removed the pump from the tank and put a pipe with a screen in its place.

The motor mounts will be fun, It would probably be easiest to buy a tubular K with traditional SBC mounts on it, but you could get some out of another car, measure and weld some traditonal clamshells in.