Power Valve Selection

This carb came with the 64 jets, which I thought was fine since the original 4160 holleys came with the 64 jets. I do have jets ranging from 61-70, I also have the holley kit that includes different squirtter sizes, accelerator pumps, and cams. I do not have a stock of PV's (just a 6.5 sitting on the shelf)

Is there a way to determine when I need to go bigger/smaller jets? Besides reading vacuum, is there a way to determine PV sizes? Is there a section of the carb I should be adjusting first (jets, accelerator pump, pv)? I currently dont have an AFR gauge and dont have the means to add in the O2 sensors close to the exhaust manifolds.