21 The distributor is a billet unit from MSD. Besides its excellent performance, one of the great features of this distributor is the adjustable collar. This collar determines the depth which the distributor extends into the block. By adjusting the height of the collar, you can precisely set the distributor gear engagement with its mating gear on the cam. Taking the time to make sure the distributor gear isn’t bottomed out against the cam gear (you should be able to move the rotor up and down a bit by hand) will not only help the distributor gear last longer, but it also helps everything spin more freely.