The thinking behind sealing the gasket to the head is, the head has a very low profile (or Dam) to hold the oil inside of its parameters. By sealing the 7/16" new gasket (get the thicker one folks!) to the head, you are creating a higher wall to retain the oil so it doesn't leak down the back where they think they have a rear main seal leak when they do not. It will usually leak just down the back because of the 3 degree back slant of the engine. By not sealing the valve cover side, its easy to pop the top without an oil mess. I learned that from one of our Kansas good ole boys! I do not paint the surface where the valve cover meets the head. Gasket sealer seals better without paint in the way. But you DO have to be delicate with the wrenches during a valve adjustment.