Hard to tell (at least to me) from the Original post if we are talking about the truck or the camper.
Tire pressures are one of the most heavily discussed areas of the forum and many threads exist here about them.
Running max sidewall pressure may be "safe," but overkill and may lead to handling problems when the truck is empty (or not towing) due to tire bounce.
Only knowing what each axles weighs and adjusting the pressures regularly for your actual implementation will you have optimum ride and even tire wear.
As always tire pressure per axle should always be the same. If an axle's weight bearing shows that one tire on that axle is supporting a weight requiring 75 PSI and the other tire on that axles has a load requiring 65 PSI, then both tires must have 75 PSI.
For trucks, if the front axle needs 65 PS and the rear axle is supporting a load that needs 75, then that is how they should be inflated; regardless of sidewall. You should also never have less than your pillar pressures.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW