My problem was that short shaft pump made the fan hit the balancer and lower position it hits bottom radiator connection.
First I added a spacer to move the fan forward to clear the balancer and smaller diameter to miss the rad. connection. I used a 15" flex fan from Summit.


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