According to Truck Trend, GM's newest heavy duty pickup trucks will pick up quite a bit more power and torque. The publication spotted a recent GM Powertrain ordering catalog that had the engine specs for the 2017 model year and managed to get some screenshots before the catalog was taken down, and they can be viewed here.
The screenshots revealed that the 6.6-liter turbodiesel V8 powering the Silverado and Sierra heavy duty models will boast 445 horsepower and 910 lb-ft of torque. This is a substantial gain over the current models' 397 horsepower and 765 lb-ft of torque, and as Truck Trend points out, it exceeds the Ford Super Duty line's horsepower output of 440, but comes short of the 925 lb-ft rating.
Truck Trend credits part of this output gain to the new intake system GM will introduce on the 2017 heavy duties. The intake gets 60 percent of its air from a scoop on the hood, with the other 40 percent coming from behind one of the front fenders. GM doesn't reveal horsepower figures in the press release about the scoop, but it does say the cooler air helps with maintaining the engine's output, and that the scoop does produce a ram-air affect, providing more air at speed. As we know, more air plus more fuel equals more power, but there's likely more to the power increase in this engine than only the intake.