I have a question about gasket cement on head gaskets for small OMC motors. The early service manuals (1960’s) do not recommend gasket cement on head gaskets, but the new manuals (1980’s+) state to put OMC gasket cement on the head gasket. Any suggestions? Also, the head on my JW20 3hp Johnson is warped about .003″ and is leaking water at one of the corners. I can try to use a surfacing block and 180 grit paper to improve this. Any suggestions? Thanks Jonathan