The "low water pump" engines were needed in midyear 55 so the fan would clear the lower hood profile when the body style changed. If you try to put an early 55 engine in a 55 2nd. series truck, the fan would hit the hood.
Jerry
So to confirm: The "low water pump" 235 engines were fitted in 1955 Second Series / Task Force trucks, introduced in March 1955.
The earlier "high water pump" 235s were fitted in 1955 First Series / Advance Design trucks until production ended in March 1955.
