I have an 08 GMC 2500 and tow a 38 ft. 4 slide 5th wheel.if I max out the load on the camper I would be over the advertised rating. But as used I`m just under. as for as wearing out items like brakes, axles,bearings and frame,these parts are shared between the 2500 and 3500 minus a couple of tires and springs on the rear.
as for the original post i would have to say that 5ver is too large for that truck.a 3950 will probably measure around 42 ft. and about 1500-1800 over weight.
as for pulling it the truck will do it, but without any margin.I have weighed mine and am just under on the rear and when loaded the front axle actually losses about 80 lbs compared to the weight of the truck minus the camper.