Seeker,
My 2001.5 Dodge 2-series 4x4 Cummins has a GVWR of 8800 pounds. I too have a load rating of around 2500 pounds of cargo.I have seen the ebb and flow of ratings based on a number of factors. The most important factor is/are the tires. Next is the absolute rating of the axles. Mine is 6000 pounds (or more according to Dana) front; and 11,000 pounds rear. The lawyers have their say too and bid Chrysler Corp. to downgrade the axles for safety reasons. Best not to be on the overloaded front when confronting litigation. So, Corp. rates the front axle at 5200 pounds and 7500 pounds rear with no other considerations. What considerations? My '01 RAM came with the Camper Package which added upper secondaries (aka: upper overloads) which come into play when the camper is loaded on. There is no consideration of the added payload these afford the GVWR of the truck. These are the self same secondaries that appear on the RAM 3500 duallie of the era, an era before SRW one-ton trucks, so I have in essence a 2001 SRW one ton. How can I say that? I checked all the parts differences between the frame, suspension, brakes, axles and bearings, and found only the hub extensions fore and aft, and two more, larger backspaced wheels are the difference. The rear axle on a DRW truck is wider than a SRW truck to take in to account the 7.5" backspacing of the duals facing inward. If you have the Sterling rear axle and assuming a Dana front axle you really have a lot to work with. Just beware there were two different versions of the Sterling, one having a higher GAWR. I have worked with mine and added 2 more upper secondary leaves, Stable Loads, and one more helper spring down in the pack giving me an 8-leaf rear spring pack in a sort of 3-stage system that gives a slightly worse than stock empty ride and a solid ride as the weight is added. I'm comfortable with what I've come up with in my build.
So, you can and will make up your own mind as to whether your truck is build-worthy, by adding suspension help, higher load rated tires, and maybe even higher load rated wheels. I just went through the wheel upgrade by dumping my cast aluminum wheels (with a 3600 load rating) to Stockton Wheel Steelies which have a stupid high load rating on the rear axle under the portion of the truck that takes 90% of the added weight of the camper.
It depends too on what year truck you have; whether it's gas or diesel, 4WD. The 99-02 Ford diesels are very sought after and considered by many to be the pinnacle of the International Harvester V-8 oil burners. If you have a gas engine, you will be forever afoul of gas stations to keep the tank full. Give us the info and you will get a bunch of semi-knowlegeablel replies from those own the same truck you do.
jefe