MSD's popular performance distributor. The housing is machined from a billet of 6061-T6 aluminum on a state-of-the-art CNC machine producing exact tolerances. For high rpm stability, a .500"e; steel shaft is supported by a sealed ball bearing and a long sintered bushing. This shaft also receives a QPQ coating for friction reduction and resistance to corrosion. A precision machined reluctor is attached to the shaft which triggers the magnetic pick-up mounted in the housing. This high output magnetic pick-up is the most accurate way to trigger your ignition. Plus, with no moving parts to wear or adjust, the pick-up is maintenance free! Just above the pick-up is MSD's adjustable mechanical advance assembly. For modified blocks, there are two o-ring grooves that will keep the oil from leaking down from the oil gallery. Different springs and stop bushings are supplied so you can tune an advance curve to match your application.