Lloyd,
How did you remove and install the new freeze plug? With heat, special press tool?
Did you or the one who restored your intake remove the (2) pipe plugs and the heater core hose fitting?
Jerry MacNeish restored one of my 472 intakes. It appears he left the freeze plug in the manifold when it was “reskinned” or bead blasted as the freeze plug has the appearance of being blasted.
Thanks,
Dave