If you compare the Olds 455 water pump and the Cad 500 water pump, you will notice that there is not a heater hose/water heater return on the Cad water pump. The water has to return somewhere, So while the radiator was apart for recoring, I had these hose inlets added to the left side, back side of the radiator below the radiator hose input. Figured I\'d put the water back on the hot side to assist in the cooling of the engine water.