Oil Restrictor Kit. Fits newer GM-Style blocks (including Gen V and Gen VI),.0625" orifice diameter with oil lifter galley bosses flush with bell housing face. Two per pack
- Reduces oil flow to upper engine assembly, leaving more oil available for the rod and main bearings
- Reduces power-robbing windage by reducing the volume of oil passing by the rotating assembly on its return to the pan
- Do not use with hydraulic lifters
