Drew - so the relocation bracket has nothing to do with clearance from the rad, just positioning on the rad, correct?
Yes, that is correct.
On a 1955-2nd series or newer engine, you would want a 1955-1st series or older water pump for use with the relocation plate.
Using the relocation plate gives you the correct distance from the fan blade to the radiator and relocates the water pump in the correct orientation/position relative to the radiator.
A 1955-2nd series water pump is the newer style water pump and it is not what you want. Be careful when/if you buy a 1955 water pump from a parts store - they could quite easily be the late 1955 and newer water pump (which does not work with the relocation plate).
One final complicating factor is not just the diameter of the pulley but also the fan belt groove size. 1953 through 1955-1st water pumps (on 1953 216 and 235 engines and on 1954/55-1st 235 and 261 engines) have a 3/8" belt groove. Earlier 216/235 belt groove size is 5/8".
