i ran 16psi on 10inch rims with 12.50 tires and blew it out, i wouldnt recommend it with those sizes, but with a 8in rim u should be fine

 

Psi also plays into how much the truck weigh. it you are straped to the gills with gear and know you will be side hilling all day then go up a few psi. But 15psi is the highest i would run any time i am off road. Have i rolled a bead (or 3 on moab rim z notch) yes i have. But its not the end of the world a ratchet strap, valve steam remover, and a Co2 tank you are as good as new. You need to keep learning your set up, Stock 4runner i run 12psi and am happy there, if i crawled the 4runner more i would go lower. If you dont blow a bead every now and then you are running to much air pressure.

 

the only think that hangs my truck is really soft and/or really deep mud. i have michelin ltx m/s 31 10.5s, basicly a an a/t street tire. ive gone in sand so soft i was about up to my center caps in Galveston an it just trudged through. and that was with a bad clutch and injector. ive only been on rocks one time and i was plesently suprised at how my truck did. all i want to do for know is upgade tires and lock the rear diff. oh and mabey bj spacers and springs. but in your case i think your golden. i was going through the same sand as the lifted jeeps with the huge mudders and light bars and what not with my stock old 90 runner on the dunes
oh and i didnt even air down cause the driving distance to the closest place to get air

 

Hmm. Well, to each his own.

I run 17 psi all over colorado and moab. I've never been stopped by tire pressure, ever. Only breakover and departure angles.

As you say, dual ARB's and a whole lot a running gear has a lot more to do with the game than tires.