Posted by Bob on Wednesday, June 29, 2005 at 9:56PM :
In Reply to: O.T. Old furnace fan for garage posted by Bill K. on Wednesday, June 29, 2005 at 12:27PM :
just put one of the smallest, a 2" or 3" on the motor and don't worry about it. That runs it at the at the safest load/speed. A larger pully will spin the fan faster but could overload the motor.