Comes with an FHP420 cam & 8.2 compression ratio. The S&S KN-series (Knucklehead style) engines come very close to the original but it is not a replica engine. A number of improvements/changes were made. It comes with 48-99 engine mounts and will not fit OEM Knuckle frames. A later; 58-65; style flywheel assembly is used; with the splined sprocket shaft and a Timken sprocket shaft bearing for increased strength. Therefore a 54-65 style tin primary and motorsprocket must be used. Rocker arm cover ''tins'' are also improved over stock. The lower covers are made of die-cast aluminum; and instead of being held in place by the valve guide; they are held down by valve spring pressure. A special gasket on the bottom of the lower ''tin'' provides a good seal and easier access for servicing; since the valve guides do not need to be pressed out in order to remove the lower covers. Instead of the steel brazed-in hard oil return lines used on stock tins; S&S has improved oil line design for better reliability; access and assembly. Engines come completely assembled and ready to run with an S&S pre-set Superstock single fire ignition system and S&S Super E carburetor. Note: Crankcases come with 48-99 engine mounts and will not fit OEM Knuckle frames.Note: Special Order Product only. To order please contact your MCS sales representative.