“4 1/2” from the radiator “ is not good for optimal cooling. You also may have a air bubble in the system. Coolant should be only about 1/2 inch above the fins in the radiator. As HRL said, find out if your water pump is rotating the right way. Fill the system properly and add a properly spaced fan shroud. Start the engine and hold a piece of tissue paper to the front of the radiator. If it sucks tight to the radiator when the engine is reved up the fan (not necessarily the water pump) is rotating correctly. Good luck.