So in case I didn't mention it, the engine is already in a 1950 Chevy 3100.
Pulled the valve cover and seems well oiled, probably from turning it over doing the compression testing. BTW, I did the compression testing using a standard tester from Harbor Freight, and cranking the engine with all the plugs out and cold (since it will not currently start). Moved cylinder by cylinder and averaged 120 PSI on 1-4, and near 0 PSI on 5 & 6 when dry; slight increase in PSI when oiled/wet, but 5 & 6 still near 0. My guess is blown head gasket, but trying to run the leak test to confirm before pulling the head... which lead me down the current path of discussion.
Thanks for the feedback. I did find what seems the perfect tool for manually turning the engine "on-vehicle", a Crankcase Rotation Adapter from Preform. Will try it in the next couple of days and come back with how well it worked (or not).
