Looking to replace the water pump in my 48 Plymouth. Engine is stock 6 cyl. Every site I go to lists replacement as a gates # 42554, but when I order one I get a pump that is exactly right to bolt to the engine BUT is longer than the original. By longer I mean from where it bolts on the engine to where you attach the fan. It is about 1 1/2 to 2 inches longer which puts the fan into my radiator. Can anyone tell me where I can get the correct one ? THANX IN ADVANCE ..........JON