"2011 F-Series Super Duty, powered by an all-new 6.7-liter Powerstroke V8. The engine makes 390-hp at 2800 rpm and a tremendous 735 ft-lbs of torque at just 1600 rpm. A standard 6.2-liter gasoline, which replaces the old 5.4-liter V8, makes 385-hp and 405 ft-lbs of torque, an improvement of 85-hp and 40 ft-lbs of torque. Both engines are mated to an all-new 6R140 heavy-duty TorqShift six-speed automatic transmission .
Ford rates this new engine in the F350 to tow a max of 21,600 lbs and a payload rating of 6,520 lbs. As for the F450 model, it is rated to tow 24,400 lbs.
Chevy has yet to release engine output figures for its Silverado HD model, but at this point that’s pretty much irrelevant as the F350 outshines it in towing and payload by 1,600 lbs and almost 200 lbs respectively."