DescriptionCummins 4939587 / 5346430 High Volume Oil PumpFor 4BT, all 12v’s & early 24 Valve engines.Genuine Cummins partFits:4bt1989-98 12v1998.5-02 24vThis Cummins 4939587 / 5346430 High Volume Oil Pump produces a higher oil volume/flow and slightly more pressure than the stock 4bt or 12 valve oil pumps.Providing better lubrication and oil pressure.1986 to 93 engines will gain the biggest jump in oil pressure & flow. The 1994 – 98 engine will benefit the 2nd most. This pump is standard on the 1998.5 – 2002 motors.Don’t be surprised that pump is slightly different in size as this is how Cummins increases the volume. Bolt holes are exactly the same so no worries on bolting up to the8 valve & 12 valve engines.Instructions for installing oil pumpCummins has been building these pumps in China for years now.*** Non returnable part