Early sbc's, 265, 283, 327 before 68 I believe, used a short water pump and thin harmonic dampener/balancer and the long water pump came about when the dampener/balancer was thickened. I can't think of a lower pulley arrangement that would line using a thick dampener/balancer with a short water pump. My solution would be to use a short blade non clutch style fan with the set up you have. That is what I used on my 36 coupe after moving the stock radiator forward as far as it would go. I never had a cooling problem but then again I was never in stop and go traffic either. BTW, I drove that car from Dayton, Ohio to Camp Pendleton, Calif. and didn't have a cooling problem even running through the desert in the middle of the afternoon. I added the fan after getting stuck in line at Lions Drag Strip in late 64.