This is THE major issue when putting a late 235 into the 54 or earlier Chev, more things come into play than just the water pump. Fan in wrong place (not where it should be for keeping cool), hit's balancer, hits lower rad outlet I've see all kinds of shade tree solutions. Best one is the adaptor plate and back to early pump, also could ditch the fan all together (which is in the wrong place now anyway) for a whittled down one or electric etc. This subject and solutions should be a tech tip on the bolt.

It's easier to get forgiveness than permission!
1946 1/2-Ton Chevy
1953 Chevy 3/4-ton Factory Stakebed