Before you pull the head, it might be a good idea to pressure-check the cooling system. Since the old stovebolt radiators don't handle pressure much over 4 to 7 pounds without risking damage, I like to remove the hoses from the radiator, plug one and adapt a garden hose to the other one. Bypass the heater core by looping a piece of heater hose from one port to the other. You can presurize the block and head that way without risking radiator or heater damage. Once the pressure has been applied for a couple of minutes, spin the engine over with the spark plugs out to see if you've got a leaky head gasket or a cracked head. If water squirts out of one or more plug holes, you've found the leak. Water from the oil pan drain plug without leakage into the combustion chambers indicates a freeze crack into the crankcase. Be careful not to over-pressure the block with the hose, just turn the water supply valve on a little and maybe create a small leak with the block drain petcock to avoid getting full water line pressure on the castings.
Jerry
Last edited by Hotrod Lincoln; 01/18/2011 2:36 PM.