General Motors has unveiled two new sixth-generation Small Block V8 engines for the 2027 Chevrolet Silverado 1500 and GMC Sierra 1500. The lineup includes a 5.7-liter L76 engine and a 6.6-liter L78 unit, both designed for the next generation of full-size pickups.
The 5.7-liter L76 engine produces 402 horsepower and 428 pound-feet of torque. It replaces the previous 5.3-liter engine by increasing the stroke by 6.0 millimeters. This configuration allows the 2027 Silverado 1500 to tow up to 13,700 pounds, while the Sierra 1500 reaches 13,500 pounds.
The 6.6-liter L78 engine delivers 481 horsepower and 501 pound-feet of torque, replacing the outgoing 6.2-liter V8. Despite higher power output, its towing capacity is rated at 9,700 pounds for the Silverado and 9,400 pounds for the Sierra, focusing on performance.
Both engines feature direct and port fuel injection, higher compression ratios, and redesigned intake manifolds. While they share bore spacing with the Corvette LS6 engine, these truck-specific versions are engineered for hauling, towing, and off-road driving requirements.
Production of the new engines will begin at the Flint Engine Operations facility. GM plans to expand manufacturing capacity to the Tonawanda Propulsion plant in New York and the St. Catharines Propulsion site in Canada, with availability starting later this year.
