That is a quite the challenge right there.
I am sure that you have considered:
Water pump pulley diameter difference.
Crankshaft pulley diameter difference (?).
Impeller design/size difference.
Your estimates of the block hole sizes seem very close to correct. Close enough, given that you are probably looking for a percent difference in total square inches of hole area between the two designs.
Last edited by 52Carl; 07/19/2019 2:20 AM.
