^ Not alot to figure. If you research AAM 11.5" axles, AAM rates them to 10klbs. Sam axle used under duallys with 6000lb payload ratings for a total of 9klbs on the axle (round numbers).
Tires and wheels, 17s are apparently out of fashion now and only produced up to 3195lb cap rating. If you see higher ones likely they are old stock. I don't know what changed, but go spec out a bunch of 17s and see what comes up.
However any 18" or 20" newer Ram wheels fit on the older trucks and the tire selection and available tire load ratings are both much greater. Although 20s will be mostly taller than OE 17s if in the higher capacity rating sizes.
