Milodon 16238 Performance Aluminum High Volume Water Pump for Ford 4.6L / 5.4L Milodon high performance water pumps are designed for the higher cooling demands of high performance as well as cruising or towing and RV applications Engineered for increased performance and reliability in all applications. Application specific design is a direct factory replacement with all hose connections and bosses New, high quality steel or aluminum castings for durability and looks. Large diameter shafts and heavy duty bearings for reliability Close tolerance impellers increase coolant flow up to 30 percent. With balanced distribution and improved efficiency, the pressure within the block is increased to help prevent hot spots and steam pockets while improving coolant flow through the radiator To work at its highest capability, a non-restrictive, high flow thermostat is recommended