given the same weight and ride height, lower pressure in the bottom will dictate lower pressure up top (to get to the same ride height).
so if you have 60 in lowers, i would expect much less than 300 in the uppers.
when the shock compresses, the upper chamber increases in pressure. when the shock extends, the bottom chamber increases in pressure.
i think the manual recommends 90 in lowers as a starting point for a typical 5k rig, like a 1 ton jeep.
I run about what aaron said (100-120 in bottom) and 5 inches showing which is about 300-330 up top for me up front, and low 200s in rear. I'll have to find and share my spreadsheet with my ORI change log.
if you stick with 60s in the lowers and are about 5k in weight, let us know how it takes sidehills! (and show us some link pics)