Super stock heads and crankcase. S&S easy start cams. High-flow oil pump. Forged flattop pistons. Intake system not included; compatible with stock or aftermarket intake systems. 4-1/8in. bore x 4-1/8in. stroke. 9.8:1 compression ratio. Requires oil line installation kit. NOTE: Cylinder heads on these engines are specially machined to compensate for the non-stock cylinder length. As a result, they are compatible with manifolds and throttle bodies with stock length intake runners. In addition, the breather vent bolt locations have been adjusted so they are in the stock location, so stock style aircleaner back plates will bolt up to these engines.