Cork.. The rubber gaskets = never again, but I might have to give the gaskets made in Tennessee that Charrlie_s has shown one day, I have never seen them
I use gray RTV on the Valve cover and just a thin thin coat of rtv on the head and make sure the valve cover is flat where the bolt holes are, slowly snug down with a 1/4 ratchet starting in the center and work your way out, then go back and tighten slightly If I had to guess maybe 3 inch lbs not much at all.. let it set over night ..