JiMerit's info is correct regarding the later style water pump (lower mount) being used on the 3837004 block.
For future readers, that casting code was used from 55-57 on 235 car blocks/engines.
As Jerry pointed-out above, 1955 Advance-Design trucks had the higher water pump. And they had the block casting code 3733745, and late 1955 Task Force trucks supposedly had a 3836233 block casting code with lower mount water pump (but the 3837004 block might also have been used on late 1955 trucks).
It would be interesting check the engine serial number to see if 704Josh's block was a car or truck block.
