Matt B you are correct. I had to go look at my 1955.
The holes for "side mount front" are not in the 1954 and 1955 1st casting.
Dave is correct about the water pump.
It looks like I just went through an exercise in futility on my part.
It would take motor mount fabrication, a water pump pulley diameter change (rotational speed) then adding an electrical fan for cooling.
Once you add up the price tag, it's simply not worth it.
I was really hoping you could use that engine.