Denny: Could it be possible at your getting some seepage at the oil line that feeds the rocker arms doesn't that go though the water jacket maybe the solder joint on the fitting has cracked. I think if were a cracked head you would have a lot of smoke and water dripping from the tail pipe. If you can get hold of a radiator presser pump takeing out the spark plugs and pumping up the cooling system and spinning it over water should come out a spark plug hole if the heads cracked Just a thought

Paul