I hope some one out there may have the answer to this dilemma.
I have a 59-261 I am putting in a 51 1/2 ton. I replicated the shaft length from a short shaft water pump at 4 1/2 inches from the tip of the shaft to the base of the pump at the block mating surface. The front of the fan mounting hub is 4 1/8 from the base of the pump. I have a 2 1/8 deep 6.25 inch diameter pulley that locates the belt 2 inches from the block - exactly the same dimensions as the original long shaft pump and pulley. The clearance from the pump shaft to the radiator is 7/8 inch.
The problem is that the fan I though was the original fan (18 inch diameter), hits the harmonic balancer (7.25 inch diameter). The distance from the center of the pump shaft to the center of the crank balancer is 7.75 inches. Can some one tell me if they have a similar set up, what size fan will work?
Are the dimensions for the short shaft pump correct as above?
Are the electric pusher fans mentioned in some of the past threads an alternative to no fan at all?

41 Chev 2dr coupe
51 3100 w/a 261
11 Camaro RS ragtop