This is a new replacement large gear for the 1969-70 Ram Air V and the 1973-74 455SD which used a smaller cam gear and larger distributor gear to reduce wear associated with the factory 80 Melling oil pump. It is made from the same material that our standard Pontiac polymer composite gears are crafted from. It can be run on both steel billet roller cams and cast iron flat tappet cams. Like our standard polymer composite gears it will outlast all other gears and probably be the last gear you will ever buy. Gear has .491 bore but can be reamed to .500 size.
If you are using a standard cam gear and running an 80 lb oil pump (Melling 54DF) we recommend our standard polymer composite gears available in both .491 and .500 bore. They fit all Pontiac V-8, just match the bore with your distributor shaft size They can be run on both steel billet roller cams and cast iron flat tappet cams. Again it will probably be the last gear you will ever buy! They are available on our website www.bopengineering.com