For budget or stock-style rebuilds, it's hard to beat the value of Sealed Power cast pistons. They are made from high-quality aluminum alloys and feature a carefully controlled casting, heat-treating, and CNC-machining process. And, because they're designed and manufactured to exceed OEM specs, they'll provide improved reliability, performance, and a long service life. (1975-1981) Ford, Ford truck, Mercury 351M 5.8L Modified Engine replacement Cast Piston. Bore 4.00, Rings 5/64-3/16, Pin Diameter .9751. Recessed Head w/2 valve pockets, 7.9:1 Compression Ratio
