To be completely honest. The newest engine you're going to find is basically 30 years old at this point and has likely been sitting in a junkyard, or on a shelf somewhere, for probably at least 10 years, maybe more. I would plan on buying an engine swap and rebuilding the engine immediately. As far as the swap itself goes, it's NOT hard, Basically remove the KA and put the CA in. Everything bolts up. As far as wiring goes, I wouldn't use the original harness either, for the same reasons as above. Get a new harness from Wiring Specialties. TRUST ME, you're going to have a MUCH better time trying to get it running with as much new/replaced stuff as possible. But DON'T try to modify it during the swap. You'll want to minimize changes as much as you can until you have it running.