I would run them at 32 psi and see how you like the ride. I run my 315/70/17 Duratracs at 34 psi I like the ride it gives and they are wearing nice and even. My rig is a little heavy to.

 

 

+ on the chalk test. While not the same tire, I'm running 35x12.5x15s load range C tires. The proper psi will depend on many factors (wheel/tire size, load rating, rig weight, etc.). I initially was running 28 psi, but the chalk test results suggested that I need to run lower to fully use the entire width of the tire, so I lowered to 24 psi. Chalking the tires and adjusting the pressure accordingly is the best way to determine the correct psi for even tire wear for your exact set-up