MSD Ignition MSD 8517 Buick V8 400-455 Billet Distributor

The MSD 8517 is a billet distributor for Buick V8 400 and 455 cubic-inch engines, machined from a CNC billet aluminum housing and base, and built around a high-output magnetic trigger meant to be paired with an MSD Ignition Control. Shaft and trigger construction The distributor shaft is QPQ-coated polished steel, guided by a sealed ball bearing with a long sintered bushing to keep it stable across the rpm range, which is what keeps trigger signal timing accurate as rpm climbs. The magnetic pickup and reluctor are built to run without routine upkeep, delivering a stable signal without periodic adjustment. Advance and installation Mechanical advance is adjustable using the supplied springs and stop bushings. Weights and the advance plate itself start as chrome-moly steel stampings, get a QPQ coating to cut friction at the pivots, and ride on nylon pads so they move smoothly through the rpm range. The advance mechanism can also be locked out entirely for builds running a crank trigger system instead. This distributor ships with an HEI-style cap and rotor, which accepts Cap-A-Dapts, and it must be run with an MSD Ignition Control rather than a stock-style coil setup; it carries no CARB exemption. Who it suits This fits a Buick 400 or 455 owner upgrading ignition components who already has, or plans to add, an MSD Ignition Control box.