I was able to pull 7 of the 8 plugs (one would require removing the exhaust manifold) and sprayed PB Blaster liberally inside. I did find a hint of rust on the ends of a couple of spark plugs. I guess some condensation could have gotten in through the open intake or exhaust valves. I can only pray the head gasket is still good.

I'll give it a couple more trys over the next week to see if I can free it up. I'm unfortunately not a good enough mechanic to tear down an engine so if it doesn't free up eventually I'll have to just call it a loss.

Daggum this is depressing. Until today I thought I had an engine that only needed a few tweaks to get running.