The Chevrolet HEI Distributor is a favorite for muscle cars, street rods and even circle track racers. The integrated coil keeps underhood wiring clean, and for race cars, the idea of running one wire to the distributor keeps things simple. However, when it comes to performance, the stock HEI falls short. MSD answers the need for a strong, accurate and high performance HEI with our Pro-Billet HEI. The distributor is supplied with our Digital HEI Module and Coil so there is plenty of spark energy combined with improved dwell and timing control. Tig welded on top of the distributor shaft is MSD’s adjustable centrifugal advance assembly. Three sets of springs and four stop bushings let you dial in up to 24 different timing curves to match your driving needs. Plus, there’s a vacuum advance for those concerned with economy. All of this is assembled around a precision and great looking CNC machined housing. The distributor is supplied with our new cap, rotor and coil cover and heavy duty gear so it is ready to install in your engine! Note: The PN 8365 is designed to replace GM HEI Distributors that use a 4-pin ignition module.