Raises compression from stock 9.5:1 to 10.5:1 for more power, torque and snappier engine response. The high quality forged piston from JE is almost a full ounce lighter than the stock cast piston. This makes for less vibration and a smoother running motor. Includes rings, pin, clips, and top end gasket set with valve stem seals and metal base gasket. Fits the standard size stock bore.