Newbie needs help.

We have used a 4000 lb TC for many years and miles with no problems.
The tires and wheels are upgraded to 19.5" "H" rated (5000lb) with air bags and adjustable Rancho shocks. Rickson Trucks in Maryland has
developed the wheels and has a lot of know how. Google them. The SRW rig is a lot more flexible for off-road and over sand use.

Thks everybody. I have gleamed more solid info on here in a few hours than I have in a month of lurking on the internet. Sure glad that I did not throw a ratchet strap around that Artic Fox 860 and bring it home last Saturday.

You will exceed your GVW with almost any camper. With bumpers, fuel and people I'll bet you weigh close to 8k lbs so less than 2000 payload.
However, I'm on the side of staying within axle and tire limitations. GVW seems unrealistic.
I would look for an 8-10' non slide camper like a Lance 915, 920, 1010 or similar.
If you want a slide, look for an arctic Fox 811. Nice camper made for SB or LB. You won't find many used LBs as they seem like more of a SB camper. Still heavy, but very little overhang on a LB so truck will handle better.
I'm sure Buzzcut will check in soon. He has a similiar truck with a heavier camper but with appropriate mods.
I had a Lance 981, 9'10" full wall side which weighed over 4500 lbs ready to camp. I carried it on a DRW and it was a load.
Good luck.

Back to the original question? What is the heaviest truck camper I can haul without further modifying my truck with G rated tires , Sway bar , air bags etc.

Your truck was called a 1 ton for a reason, 4000# = 2 tons. plus the mods already done. Just doing the simple math, you need a duce and a half.

It's a single rear wheel. Heading to a scale now and will post more info.

Is the truck a DRW or SRW? I really can't tell from the post.

Yes, 4000 will likely be too heavy. Fill your truck with fuel, and go to a scale and weigh the rear of the vehicle. Subtract from 6800 (2 x 3400). That's going to be the tire capacity.

My guess is the rear is around 3600 lbs which will leave you 3200 total payload just considering the tires. The axle rating is likely high enough that you are good for a 4000 lb camper.

Of course, this doesn't mean you aren't overweight from the GVWR perspective. For that number, subtract weights in the door sticker. You can mitigate the tire capacity by going to 19.5s or higher rated rear tires.

Without further info to go by, my experience tells me that you will be over on your tire capacity on the rear.

Having a crew cab (like I do) places most of the camper weight on the rear axle.

You mention "manufactured weight". Does that include fresh water, propane, batteries and any options that were added- like A/C?

The brain trust here on the TC forum can help you nail this down if we have more information about the camper you are considering.

John