Use stainless steel hardware!

 

I have 315/70/17 Maxxis RAZR MT load range "D". I run 36 PSI f/r. They are on American Racing AR172 BAJA AR1727885B Satin Black 17X8 5X139.7 with a 2 inch front leveling lift. Rear tires don't contact anything. Front tires rub the rear of plastic inner liner a bit. When at full lock l/r there in no rubbing. Mine is a heavy duty with another spring in the rear spring pack. I don't see the truck hauling anything heavy so that's where the load range "D" comes in.

I use chalk on the cross section of the 4 tires, roll it and check to see where the chalk came off and adjust air pressure till the chalk comes off the cross section of the tires.

 

There are also temperature sensitive strips that you can lay across the tire. Hotting in the center, drop pressure a couple pounds. Hotting on the edges, raise pressure a couple pounds. Fussy, but, can be incredibly accurate.