Hi guys, I was wondering if someone could please help me out with an American Pontiac question. I am about to replace the water pump on my 1962 GP 389. I see part numbers for two different 4 stud pumps, one that is clockwise and one counter clockwise rotation. These are special order pumps and I would like to be able to determine which one I have before ordering and without removing my existing pump. Any help would be greatly appreciated.