My wife had an 05 Ram 1500 SLT, 2wd, with those sized tires. Inflation pressure was 35psi on the door jamb, I think someone missed seeing that size on the Firestone site, it's there.

Owner's manual should have it too, for all factory installed sizes. To save you the search they are all 35 psi.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.