from allpar:

A boost in Cummins diesel power announced in February 2011 raised diesel torque (with automatic transmission) to 800 lb-ft, keeping peak horsepower at 350 but adding 40 hp more at lower engine speeds. At the time, Ram’s CEO announced that Ram pickups have the largest brakes in their class, and the most powerful exhaust brake in the class was standard. The diesel, unlike its competitors, does not use urea or any other diesel exhaust fluid.

The extra power is handled by a new, higher-rated torque converter which is better integrated for higher towing capability. In addition, a new dual-rear wheel axle with 4.10 gear ratio, new rear-axle pinion, new helical gears, upgraded bearings, and finned aluminum differential cover are used with the maximum towing package; a new engine-mounted oil-to-coolant transmission cooler and upgraded power steering oil coolers will also be used. The result is a best in class GCVW of 30,000 pounds and towing of 22,700 pounds. The high tow ratings meet all 2013 model-year SAE standards.
Manual trans cummins (the only HD one can get with a manual) will soldier on with 610ft-lbs.