GMC introduced Sierra HD heavy off-road pickups with 6.6-liter engines (3 photos)
American GMC introduced off-road versions of the Sierra HD with 6.6-liter V8. Pickups were first prepared for operation on rough terrain. Two options are available - AT4X and AEV Edition with technically similar upgrade. Ground clearance has been increased by one and a half inches (38 mm), underbody protection installed, suspension improved, reconfigured transmission and change the wheels. 
GMC Sierra HD with AT4X package stands out with mud tires 35" OD, aluminum bottom plates and decor. The front suspension is new: both the upper and lower arms have changed, upgraded steering knuckles. The stock shock absorbers have given way. racks MultiMate DSSV. Behind there is a new electronically controlled differential, and to the modes of operation of the 10-speed transmission was added Off-Road preset. 
The alternative is a more aggressive revision of the AEV Edition. Options AT4X package rethought: aluminum plates on the bottom are changed to steel, custom 18-inch wheels are installed, “power” bumpers with built-in winch and powerful towing hooks. Heavyweight pickups are offered with 6.6-liter V8 engines: turbodiesel Duramax produces 477 forces and 1322 Nm, and the atmospheric gasoline unit Vortec is designed for 407 forces and 629 Nm. 
GMC does not disclose prices for heavy pickups with factory off-road options. Details will appear closer to autumn: to this moment the hardcore Sierra HD of 2024 will start to appear in American dealers. Even earlier they will start selling more utilitarian a variant with similar equipment under the Chevrolet brand.
