hi franklin, Maybe the worksheet on this site will help. Worth a shothttp://www.ptohydraulics.com/ptosheet.htm
I can look at my model # and give you that if it will help
These are the three ratio combos I've found
4.02,2.41,1.41,1.00
5.11,3.03,1.79,1.00
6.32,3.09,1.68,1.00