What did the head gasket look like when the head came off? Any chance you had a gasket failure that allowed coolant to get past the gasket to the oil drainback into the oil pan? I am spit balling a little here because I have never taken a 216 apart but thinking there must be some similarity to how the oil from the rockers drains back to the block through the push rod holes in the head, then to the pan through the drain ports in the block near the lifters.
