Remove the MSD cap and race rotor and youll find easy access to the adjustable mechanical advance assembly. This advance is designed for accuracy and strength with rig-welded weight pins, nylon pads for smooth movement of the weights and a QPQ coating for friction reduction. Different advance springs and stop bushings are supplied so you can custom tailor a timing curve to fit your Chryslers needs. Supporting the advance assembly is a hardened, polished steel shafeet Two ball bearing guides are used to support the shaft producing incredible stability. Precision paddles of a zinc-plated reflector pass a maintenance-free magnetic pick-up creating a trigger signal that tells the MSD to fire.