One of the most important features of the MSD Pro-Billet Distributors is the adjustable mechanical advance assembly. The mechanical advance, sometimes referred to as centrifugal advance, allows you to accurately and easily modify the advance curve to match your specific application. MSD engineers have spent many hours at the dyno controls and in our labs perfecting this great distributor feature.
A variety of timing curves can be achieved simply by changing the advance springs and stop bushing. The stop bushing determines the amount of mechanical advance that can be achieved. Each distributor is equipped from the factory with the blue (21°) bushing installed with five other bushings included; Red allows 28°, Silver 25°, Green 23°, Purple 19° and Black for 18°.