Your welcome. Good choice on a 1750 motor, and turning the pump slower. I probably would go even slower myself just for the noise factor but nothing wrong with the compromise of cfm/noise your making, still will be much quieter than at 1200 rpm.
If you have never installed a pulley with seperate hub just make sure you do it evenly and do each bolt in steps. Don't over tighten them, use the specified torque. And if you really want smooth you can put an indicator of a mag base and eliminate all wabble in the pulley by tightening the corresponding bolt to the highest reading. Can get the dead nuts if the manufacture did them point.