Complete oil pump assemblies to solve oil supply problems on OHV Big Twin engines 1936-up except Twin Cam models. Can be used to update bikes with earlier cast iron pumps or as a direct replacement on later models with aluminum pumps. The pump body is CNC machined from billet aluminum which enhances the overall appearance of any engine. Compared to 1936-67 pumps the S&S product delivers 33% more oil. For maximum versatility they feature various fittings to either duplicate the original oil line routing or tailor one to suit custom requirements. Installations on engines from 1936–69 are strictly bolt-on, also engines 1981-up require no modifications. Other crankcase year groups require a simple drilling or plugging step. For this purpose a special metal drill jig is required and available.