The DragRace Concepts B6.1 Gear Differential Rebuild Kit features an improved casting design over the factory parts. This improved design makes for an ultra smooth differential action right out of the package. 7075 T6 hard coated cross pins replace the factory plastic design for a stronger differential. The kit includes all shims, pins and O-rings required to service your differential. Pair with DRC-494 for the ultimate in durability and smooth differential action.