It depends on the beach conditions. I usually air down my 33's to 18-20psi in normal conditions but on the North side of Indian River Inlet it can get pretty soft during dry spells.
Airing down helps in not stressing the drivetrain and not chewing up the beach.
I'll bet the Olson Brothers will be making some good aftermarket parts for the 6G soon.
Ford - Early Bronco (resincastmodelparts.com)
I was able to do a close replica of my 1974.