MSD Circle Track HEIMSD engineers have worked tirelessly to perfect the new circle track HEI. A 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 max RPM. At the bottom, a QPQ coated steel gear will run lap after lap, race after race,