Thanks for the responses but this is not what I'm looking for. The pump has a 9"pulley and the motor pulley is 11/2. 9 X 3.14= 28.26 1.5 X 3.14= 4.71

28.26 div by 4.71= 6 1750RPM div by 6=291RPM @ the pump

3450RPM div by 6= 575RPM @ the pump

I understand the math but my question is what RPM do I need