MSD Circle Track HEI distributors were designed with the demands of racing in mind. These "stock appearing" units are peaked and tuned to provide ultimate reliability and strength to run circles around the competition. The bulletproof ignition module fires a high-output coil in the cap, while a specially designed, QPQ-coated chromoly advance cam and weight set ride on TIG-welded weight plate pins and a TIG-welded distributor shaft. This combination provides brute strength and precision timing from idle to maximum rpm. At the bottom, a QPQ-coated steel gear will run lap after lap, race after race, victory after victory without fatigue.