MSD Performance first produced the after-market distributor, made from a billet of 6061-T6 aluminum. These Pro-Billet Distributors can now be purchased for the majority of popular domestic V8s, as well as for a number of other popular engines. There are several different versions of after-market distributors on offer. Some things are the same throughout the distributor line, like the seal design and upper ball bearing to guide the QPQ-coated shaft and the pickup that is non-magnetic, but several lines are also designed to suit different specific applications....