Steel Shim Head Fits 1958-1976 Ford 332-428. 4.420 Inch Bore, .020 Inch Compressed Thickness Mr GasketMr. Gasket Embossed Steel Shim Cylinder Head Gaskets are for high performance street machines, drag racing and oval track racing. This is a very unique design that has a solid metal on metal fold at the combustion seal. This fold makes for a very stout seal that is almost the equivalent of a higher end MLS (multi layer steel) Gasket with a Gas stopper layer, but at a much lower cost. This Gasket also has embossments around the coolant and oil passages