I think I have things figured out for now. Took the exhaust manifolds to the machine shop to the the old studs pressed out and new holes tapped. That's the easy part. The next step is getting my pulleys to line up right without things hitting. I'm running a mechanical fan, so I'm going to have to get a clutch or a spacer, since it's rubbing on the crankshaft pulley. Then the flat pulley is also rubbing on the timing tab. The 4.3 was originally run with a serpentine, and long pump, and I'm going v-belt and short pump so I can reuse my pulleys and alternator w/ brackets. I'm also going to have to find a spacer to fit on the harmonic damper of the 4.3. It has a lip, and the holes are recessed. I need to measure it and find out if any of the spacers at Summit will fit and not push everything out too far or not enough. Fun stuff.