Ford 360 (1968-1976) Big Block Hypereutectic Piston - Flat Top Four Valve Relief Piston. Bore (in): 4.050 in. Bore (mm): 102.870mm Piston Style: Flat top, with four valve reliefs Piston Material: Hypereutectic aluminum Wrist Pin Style: Press-fit Pin Diameter (in): 0.975 in Piston Ring Thickness: 5/64 in. x 3/32 in. x 3/16 in.