New Moroso valve cover gasket set.  These are a performance rubber gasket with steel core.  3/16" thick.  For aftermarket valve covers with flat bottoms only. Fits the following:

Fits 302/305/307/350/400 Small Block Chevrolet engines, 1986 and older (perimeter bolt)

NOTE : These gaskets are not for use with covers with gasket lips.  These are slightly wider than OE style gaskets for better sealing.