Holley Godzilla High-Mount Accessory Drive - OE Oiling System - Base Kit - BlackThe accessory drive components in this system can be configured in several different ways. For example, there are alternator options available for different performance and electrical demands. Also, deleting the A C and or P S are options. This "base kit" supplies all but the components with options. If you purchase a "Holley complete kit," all these options are already chosen for the most common, cost effective combination.