Anyone want to guess what would cause air bubbles in the coolant? The overflow can is showing about one small bubble a second or so whenever the engine is running. The only thing I can think of is head gasket, cracked head or cracked cylinder.

 

I fear you hit the nail on the head already. I used to check older cars for head gasket leaks by removing the radiator cap (when just warm) and the waterpump belt. If you see bubbles or fumes in the radiator you got a problem. Cain't think of any other cause. Sorry.