Can Our F350 Carry a Lance 1191 Safely?

There are in fact plenty of companies that up fit work trucks all day everyday. They are in fact certified by the truck manufacturers to "relabel" the trucks. I am in the construction business and have driven quite a few bucket trucks and other work trucks that have an "aftermarket" GVWR sticker on the door jamb.

I think everybody on this thread understands the role of an upfitter. My point was 'why'? The OP can purchase a F450/550 or 4500/5500 truck to carry the camper that does the job, is built for it, and keeps the OP within payload and under gross without modifications if that is a major consideration. And purchasing new is not necessary. But, of course, to make a sale the dealer will always try to find a way to make what you have work. They know if you have to purchase another truck and the camper that you perhaps will not purchase either. And unless the upfitter modifies the brakes the job is only partially done. And since the OP asks if it can handle the 1191 safely, brakes have to be a consideration. And that is what I said in my original statement although maybe I was not as clear as I could have been.

The other side of the coin is to put the 1191 camper on the 350 and see how it handles it. Get up to 50 mph and stand on the binders and see how it stops. Swerve around an obstacle and see how it handles it. Then at least the OP has a starting point to work from and can determine what modifications will be needed. I certainly don't think it is the end of the world to be a little over gross, but not over axle or tire/wheel ratings.

Ford has a Towing Guide and a section just for carrying a cabover camper. Might be a good starting point for the OP to consider how much modifications would be needed to carry around 5000 pounds with his truck.