replace 216 engine with 235, what should be done with the water pump? The shaft is to long to fit behind the radiator!

. You could try a shortened water pump but your fan will hit when you crank and doesn't cool as well. Best method I've found in on web page < http://la.znet.com/~r1937/WPump.htm >.
I had a plate made up for $40 so would suggest making it your self.
. Good Luck, . Lou