Canton 22-560 Billet Aluminum Oil Input Adapter Sandwich Style Big Block ChevyThis BBC Oil Input Adapter and Bypass Eliminator, Mark IV, provide two 1 2" N. P. T. oil input ports, one before filtration (for an external oil pump) and one after filtration (for an Accusump). It mounts between the oil filter and block and bolts into the mounting holes left after the bypass is removed. Removing the stock bypass allows the engine to receive filtered oil all the time. The filter is lowered only 1 1 2". Comes with hardware and O Rings.