These Milodon water pumps are available in high-volume (steel or aluminum) and standard-volume versions. All pumps feature new castings, large-diameter shafts, heavy-duty bearings, and are direct factory replacements with OEM hose connections and bosses. The high-volume pumps have a balanced distribution design (equal flow to both sides of the engine block) and a high-efficiency impeller that increases coolant flow up to 30 percent over stock. These features increase coolant pressure in the block to prevent hot spots and air pockets and improve coolant flow in the radiator. A high-flow thermostat is recommended when using a high-volume pump.