The Stovebolt Site Forums The Shop Area Engine Shop Fan, Water Pump and Harmonic Balancer

1952 216 - low pressure - high water pump - top nuts on the valve cover
1953 235 - high pressure (Powerglide) - high water pump - top nuts on the valve cover
I could not find a 1953 car/truck low-pressure engine - high water pump, top nuts on valve cover
1954 235 - high pressure - high water pump - side screws on valve cover (no top nuts/bolts)
1955 235 (car) - high pressure - low water pump - side screws on valve cover
1957 235 - high pressure - low water pump - side screws on valve cover

Notice how the later 235s (1955 and later) have a wide pulley behind the fan. This style water pump locates the fan further out from the engine than the fan on earlier engines. The JC/etc "short-shaft" water pump eliminates that pulley, and it has a smaller diameter pulley, nearer to the block. Thus/therefore, the fan hits the harmonic balancer.