When General Motors recently previewed its completely revamped Chevy Silverado and GMC Sierra Heavy-Duty pickups to automotive journalists, the event included a display of stripped chassis that allowed the media to compare the previous models side-by-side with the new ones. Last year's versions were supremely capable work vehicles, among the best trucks ever built. But the 2011 pickups are an awesome step up in just about every capacity.

For starters, on the 2500HD (three-quarter-ton) and 3500HD (one-ton) models there's only one carryover part in the entire framework (which is shared by the two vehicles): an almost insignificant stabilizer-bar link. Every other chassis component – from the fully boxed frame that's five times stiffer than the 2010 chassis, to its standard 17,000-pound-rated conventional tow hitch – is bigger, brawnier, and brand new.

There's also a new 6.6-liter turbocharged diesel engine option, with 397 hp and 765 pound-feet of torque, matched to a fuel-conserving Allison six-speed transmission – a somewhat scaled-down version of the tranny used in the U.S. Army's mammoth M1 Abrams battle tank, according to GM engineers. GM's reliable, proven 6.0-liter V8 gas engine (360 hp with 268 pound-feet of torque) is also available.

Other goodies in the new Heavy Duty pickups include a "smart" exhaust-brake system for controlling hill descents and a trailer anti-sway system that automatically activates when the truck knows it's needed, coordinating brakes, transmission, and engine speed without driver input. And for the GCs and other high-rollers, there's a first-ever four-wheel-drive, definitely upscale, crew-cab Denali model, offered only in the GMC Sierra 2500HD series.