Hi,
Car has been parked since 1966. Pulled head to free up some stuck valves. Triple checked replacement head gasket to make sure it was right.

Coolant in radiator and in top half of engine as I fill radiator and can squeeze top hose and coolant comes out of radiator. Have a freeze plug out and there is no coolant in the block. Freeze plug came out when blowing air in the block drain with radiator cap off, blew plug out. How could there be now flow at all, in fact plugged between radiator and block?

Thanks

 

One bad freeze plug says you need to replace all of them after setting all those years.

 

Sounds like the thermostat is frozen shut