This is a replacement heater hose adapter for high mount accessory drive system. Holley's high-mount accessory drive has everything pulled up and in tighter than other options. The patent pending accessory drive incorporates the timing cover, water pump, and alternator and can also be configured with A/C and/or P/S if desired. This system works with the factory crank pulley, as well as aftermarket damper/pulleys. Includes timing cover/water manifold, water pump, and alternator bracket. The 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.