General Motors has revealed a new Chevrolet Silverado HD and GMC Sierra HD, which have been significantly refreshed for the 2027 model year. The heavy-duty trucks get new engines, including a diesel 8.3-liter V-8 with 1230 pound-feet of torque, and they adopt an electric rack-and-pinion setup.The new HD trucks are expected to go on sale by the end of the year, with prices to be released before that time.