Cover, Valve Polished Aluminum (Center Bolt Design) These die cast aluminum valve covers are polished to give them a bright shine. They are used on all 1986 and newer Gen I and 2 engines with center hold down design. They are approximately 1/4 inches taller than production covers. Shipping is not included. Item 12497978 Picture is of the Black Aluminum Cover Technical Notes: Use rocker cover gasket P/N 10046089 and replacement bolt and seal in kit P/N 12497980. (The kit includes two valve covers, eight bolts, washers, and seals.)