I donít own the 3.0 Duramax but that article seemed off to me. With an aftermarket tune my 3.0 diesel will hold to a 6 percent grade up to 6,000 pounds without using the TBC or the truck brakes.
With a proper sized WDH and axle to frame air bags a half ton should be able to handle up to 1,150 pounds of tongue weight for this example nothing in the bed according to the Mfgrs and by SAE j2907. In practice I have found this to be true assuming you used your WDH and loading to adjust your axles & tongue weight to optimum or at least within maximum spec. If you fail to adjust it to get the weight back on the steer axle lol all bets are off.
Transportr AS & TT Mfg 2 dealr RAM ED factory brake controller tow mirror hitch camera & receiver 1,290/12k, No sway WDH, Adj. hitch, axle 2 frame air bags, tune w turbo brake, SLT Grill, 31.9" load tires, Max ED tow 9,200, GCAR 7,800, Max Ram 1500 GCVW 15,950, truck hitches steer 3,240 drive 2,560