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. Bore (in): 4.000 in. Bore (mm): 101.600mm / Flat top, with four valve reliefs /Cast aluminum. Piston Ring Thickness: 5/64 in. x 5/64 in. x 3/16 in. - Wrist Pin Style: Press-fit - Pin Diameter (in): 0.928 in.