To properly position the fan, you need to purchase an adaptor plate (pre68 Dave, on this site) that uses the old style waterpump. Both 3/8 and 5/8" pulley width pumps are available from NAPA. The plate requires drilling and tapping a couple holes but you use the adaptor plate as a guide and for the most part it is not that complicated. This moves the fan up about 4" and gives you additional fan/radiator clearance.
I tried a "short pump" in my 56 engine in a 54 truck and found that the $40. adaptor plate and earlier pump (41-54) was "the" solution to my cooling and clearance problems. This also allows you to use a stock water pump that is readily available over-the-counter.
The instruction sheet he provides is detailed and warns that you should avoid using a 55-62 passenger car balancer as it will overspin the pump.
I have a couple pictures of the early pump and the adaptor plate on pg 3 of my webshots "shoebox". I hope this helps.
