Hi Everyone, I appreciate the effort everyone is making to help. I'm going to say up front that I'm at the end of my rope with this project and about to give up. So with that in mind, please forgive me in advance if I seem snippy in any way. I'm really just worn out with the whole situation and very close to just parting the whole thing out... and that's saying a lot because I've really put a lot of time and energy into the car.
Today I worked on verifying that the camshaft specs match what's on the card. In my continuing string of bad luck, the dial indicator magnetic base I bought from sears this morning was bad. The magnet was nearly dead. When I returned it, there was one more on the shelf... same thing! So I had to rig up my own base using a piece of wood, some vice grips, two towels and the main shaft from an RC helicopter. As such, I was only able to position it over the exhaust valve so I haven't confirmed the intake side of things yet. Still, pretty much everything I've checked or replaced on this build so far has turned out to be fine, so I'd be willing to be the cam is fine.
I was able to verify the lobe lift and the exhaust valve closing (@ .050") relative to TDC matched the cam card. That tells me I've got the cam I ordered.
Basic specs on the car: 350 cu in, 4.000" SRP pistons 24cc dish, Total Seal rings, Cometic 4.030 head gasekets .040" thick, stock deck height, est 8.6:1 compression. Cam is Comp Cams Hyd Roller 224/224 @ .050, 114 sep, .539"/531" in/ex. Stock everything TPI intake except polished and 65 lb/hr Precision Turbo injectors. Fuel is single Aeromotive Stealth 340 in-tank. Megasquirt ECM with PLX WB O2. I keep the AFR between 10.9 and 11.2 in boost. I can't remember my current total timing since I've been moving the boost around trying to troubleshoot things, but it's high 20's in the 15-18 psi range and I didn't feel safe going higher. Haven't ever heard detonation in this new engine but did run into it a few times with the original iron head engine. Transmission is a 700r4 with a 9 bolt 3.27 rear. Ignition is stock small top HEI, MSD 6AL, MSD 8mm wires, AC delco plugs 2 heat ranges cooler than stock 91 Corvette uses, gapped to .025", at the moment a Blaster 3 coil but normally MSD Street Fire external HEI. Turbo is a Precision PT6766 billet.
I'll work on getting pics of the distributor cap and rotor.
Obviously there are hundreds more details but hopefully that narrows it down a bunch. Here is the engine (with the old ebay turbo on it):
