Good grief…the factory rated payload is on the door sticker.
However you won’t like what you see. (And if it has a lower optional gvwr rating and correspondingly lower payload, know that that is very false and use your configuration at max option gvwr and add the difference to your rated payload for an accurate max yet somewhat conservative payload.
Although payload will be be better with the gasser under the hood (even though that has virtually zero real world effect on rear axle payload which is 98% of the equation for a TC).
The fact that it’s an original chassis Super duty makes it a little twisty-er than any GM or Ram from the mid 2000s up. But it’s not weaker.
Stick to sub 3500lb empty TCs and plan on beefing up the suspension a bit and you’ll be ok in the 4k range up to about 4500lbs tops. Any more than that and you’re blowing out of the tire/rim ratings by somewhere between a little (which doesn’t bother me) and a lot, without going to Method wheels and big tires or 19.5s (an option in conjunction with good suspension enhancements).
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold