[Sam Mac]

This is a strange one. How many hours on this engine? The one I mentioned burned the head gasket between the cylinder and the oil return. I also had one that the exhaust valve guide moved up in the head this in turn caused a push rod to bend. When you replaced the head gaskets did you resurface the heads? They are notorious for warping. They are easy to resurface with a piece of glass and some wet sand paper. Here are a couple before and after pics of the one that I did most recently. If you look at the first pic you can see the place that burned through into the oil return.