The Stovebolt Site Forums The Parking Lot Big Bolts C60 tire pressures

There are also different pessures depending on the load you're carrying and wether you're running single or dual. Typicaly the max pressure is lower on duals than singles.
I could be wrong (I'm known to be more and more frequently as I get older,...), but I was under the impression that DOT standads require the max pressure & load limits stamped on the sidewall. Primary reasoning, all tires are NOT rated the same regardless of size & your tires may be too weak for your max load. If you get pulled by whatever branch of your local law enforcement that handles trucks, they are gonna look at that as well as your rated gross on your registration. They see a 10Klb truck with a 2Kgal tank, little quick math, a look at your tires,... Run light tires on a heavy truck you're gonna have a light wallet in short order.
Also, just a personal opinion, but if you're running rubber that's old enough not to have those numbers on em, I'd really think twice, maybe three times, about running a capacity load on them.