Actually, there are several ways for the oil to get contaminated with coolant,and the head gasket is the least serious. Heads, and even cylinder blocks have been known to develop cracks, from overheating, freezing, and occasionally just from old age. Before you pull the head, I'd reccomend a pressure check of the cooling system to try to isolate the source of the leak. Disconnect both radiator hoses and splice them together, and make a loop of heater hose from one connector to the other. Now you can adapt an air line with a pressure regulator to the cooling system, and apply about 20 pounds of pressure. With the spark plugs, valve cover, and the pushrod cover removed it might be possible to pinpoint the source of the leak. Sometimes pulling the head will hide evidence of where the leak is coming from.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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