+30% increase in HP and torque over stock. Short stroke for less vibration and longer engine life. Shorter than stock engine height for easy installation. Does not include carb or ignition; use stock or aftermarket carburetor and air cleaner. High volume, high-pressure (HVHP) oil pump. Durable S&S 3-pc. flywheels. Performance 585 cam & valve springs. 4-1/8in. x 4-1/8in. bore and stroke. 9.8:1 compression ratio. Wrinkle black finish.