I used the steel reinforced neoprene valve cover gaskets. Problem is the holes in the gaskets were high in the gasket making the gasket set low on the head. plus the holes were so tight that once I pushed one gasket over the studs , it was a ***** getting it off. If the gasket bends ,the gasket gets even tighter, hard to emagine. Plus there was no fudging for the manifolf being milled to match the milling on the heads. I ended up taking a dremel moto tool and 1/8' carbide burr (rotary file) to the gasket holes. I exagerated the gasket holes downward and getting the needed freedom and moving the gasket upwards to cover th upper sealing edge on the intake manifold. Plus a little blue RTV. It isn't leaking from the valve cover anymore. Now the
oil is showing up on the right coolant pump to block flange boss. It's making a real mess maybe not as much as before but enough to worry about.