Complete kit that includes it all. The oil pump assembly complete with mounting hardware; fittings; gaskets; pinion shaft pump drive gear; woodruff key; clip; oil pump shaft driven gear; breather gear & a shim kit. The oil pump is fully CNC machined to maintain close tolerance and strict quality control. OEM width feed and return gears. For the cleanest look possible; this pump is not equipped with a rear chain oiling provision. Note 1: There may be more differences in Harley-Davidson crankcases than you might think. Plugging or drilling a hole is sometimes necessary. S&S offers a drill jig as MCS 518150. This is a special tool that is mounted on the crankcase and used as a guide to help you drill holes correctly.