I'm re-assembling my '57 371 Olds and so far there is just one part I'm not clear on and I can't find a diagram either, I checked, Motors manual, Oldsmobile Service manual, and google. This large washer with the key slot, does it just slide on the crank shaft before installing the water pump? Or after the water pump and before the pulley? If anyone knows or a picture of your engine would be helpful!!