Nice truck.
To answer your question, the wheels do not determine what PSI you should be running on what surfaces. Tire size, weight of vehicle, and the surface you are on determine the lowest PSI you can safely run. I used to have a chart that was more of a guideline to help get people started. If i find it, ill post it up for you.
For reference, when I was running 35x12.5r15s on my Jeep with a weight of 4500 pounds fully loaded down for long travel, I would comfortable run 8-9 PSI when I needed to do some rock crawling, less in deep snow. If i was running dirt roads and traveling around 20mph my psi would be around 11-12. However, if the roads where really good my PSI would be somewhere around 16. I never once blew a bead in the many years and trails I have ran. It takes time to figure out what works and what does not. Normally you can figure out pretty quickly if you are underinflated for the road conditions and risk damaging the tire just by inspecting it and feeling if the tire is getting warm.
Now that I run 33x10.5r15s I increase all those numbers by about 2 PSI or so.