With OEM style bottom feed and return oil line placement. Fully CNC machined to maintain close tolerance and strict quality control. This pump is not equipped with a rear chain oiling provision. All S&S billet pumps comes complete with everything you need to replace the stock pump and include mounting instructions. Machined with an oil pressure relief bleed off passageway & relieves pressure build up on top of the valve to maintain consistent oil pressure. Oil pressure regulation bypass routes excess oil directly to the supply side of the pump & reduces the amount of oil returned to the tank; less foaming and cavitation. Note: 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.