Crazy Horse -- I beg to differ. My method makes no assumptions. I weighed the truck with myself, wife, and dog. No tail gate. Fuel tank essentially full. "Actual weight" 7,450 lb. Went home and loaded the camper. 1 gallon of antifreeze in the water system. 2 propane tanks aboard, but nearly empty. No gear except for electric jacks, solar panel, microwave, 3 way fridge, trim and cold weather packages. No TV, stereo, or generator. "Actual weight" of the rig was 10,240 lb. Subtraction is not fuzzy math. With the air bags holding 50 lb of air, the rear axle weight was ~6500 lb. At 70 lb of air in the bags, the weight on the rear axle was ~6000 lb. And that is how I drive the rig.
Now the reason I didn't initially want to post the weights is because I’d have to admit that the rig is 1,440 lb over the max. GVWR of 8800 lb. DRY! The rig hauls fine with an estimated working weight of 11,000 lb. But I am breaking the law. Now the real question is how a Lance dealer can sell an 820 to a customer with an extended cab 4X4 when even your own data acknowledges a dry weight of 2400 lb. The sticker on mine says 2840 wet and my dealer had no qualms about adding the additional gear. And they insisted that a 2500 would carry the load with no problem as long as I had air bags. However, he would not sell me the camper without installed air bags. They didn't care if someone else put them in.
When I drove out of the dealer's lot with 40 lb of air in the bags, I found that I could not drive the rig in a straight line at anything over 50 mph. Pumping up the bags to >60 lb eliminated this problem but not the side to side sway. The Ranchos took care of the sway problem with the rear shocks set at #5. The extended cabover flexed visibly when driving on certain types of road surfaces and caused the truck to rock front to rear. The stabilizers fixed that problem and I am very happy with the way the rig has handled for the past 3 years.
IMO, you need air bags with the short bed and a heavy camper. Adding heavy springs should stop the sway problem, but the real issue is the relative weight distribution between the front and rear axles. Unless the center of gravity is shifted forward by raising the camper sufficiently using the air bags, the rig is dangerous and should not be driven. Now all of this discussion refers specifically to short wheel base 2500 trucks hauling heavy campers. I have a friend with a LWB 2500 who hauls a camper nearly as heavy as mine without air bags. He did install special helper springs, however.
So there's my 2 cents. One of these days a Lance or Bigfoot dealer is going to become involved in a law suit over selling campers that put 3/4 ton trucks significantly over their GVWR. I just hope I am not involved. I feel that Lance makes a first rate product and I am very happy with my 820.
BTW Crazy Horse, you have a really nice web site! Are you the Lance dealer in Anchorage? I get up that way pretty often.
clanders -- I run the stock Michelin 245/75/16s that came on the '99s. They wear like rocks even with my overloaded condition. I run 88 psi in the rear since I live at 5400 ft. This turns out to be 80 psi at sea level.