General Motors has released the full specifications for the two new V8 engines powering the next-generation 2027 Chevrolet Silverado 1500 and GMC Sierra 1500. The sixth-generation Small Block family will include a 5.7-liter L76 and a 6.6-liter L78, with both engines scheduled to be available when the redesigned pickups launch later this year.

The new engines increase displacement and output compared with the V8s they replace. They also bring revised intake and fuel-injection systems aimed at improving airflow and supporting the demands of towing, hauling and off-road driving.

5.7-liter V8 delivers the highest towing rating

The 5.7-liter L76 produces 402 horsepower and 428 pound-feet of torque. It effectively replaces GM's outgoing 5.3-liter V8, delivering 47 more horsepower and 45 more lb-ft of torque.

GM increased the engine's displacement by extending the stroke by 6.0 millimeters, bringing total displacement to 350 cubic inches. The L76 also uses a higher compression ratio, larger throttle bodies and redesigned intake manifolds with tuned runners. Like the other sixth-generation Small Block engines, it combines direct and port fuel injection.

Despite being the smaller engine, the 5.7-liter V8 offers the higher maximum tow ratings. Properly equipped, the 2027 Silverado 1500 can tow up to 13,700 pounds with the L76, while the equivalent Sierra 1500 is rated for up to 13,500 pounds. Maximum payload is 2,170 pounds for the Silverado and 2,140 pounds for the Sierra.

6.6-liter V8 targets performance buyers

The range-topping 6.6-liter L78 replaces GM's 6.2-liter V8. Its 400-cubic-inch displacement produces 481 hp and 501 lb-ft of torque, an increase of 61 horsepower and 41 lb-ft over its predecessor.

That extra output does not bring a higher tow rating. The L78 is rated to tow up to 9,700 pounds in the Silverado 1500 and 9,400 pounds in the Sierra 1500. Its maximum payload ratings are 1,510 pounds and 1,450 pounds, respectively.

GM positions the larger V8 for buyers seeking more performance and higher-end equipment rather than maximum towing capacity. The L78 is also distinct from the 6.7-liter LS6 used in the 2027 Corvette. All three engines belong to GM's sixth-generation Small Block family and share a 4.40-inch bore spacing, but the truck engines are engineered specifically for pickup applications.

Production and availability

Initial production of both V8s will take place at GM's Flint Engine Operations. The automaker plans to add production capacity at Tonawanda Propulsion in New York and St. Catharines Propulsion in Canada.

GM says the 5.7-liter and 6.6-liter engines will be available when the next-generation Chevrolet Silverado 1500 and GMC Sierra 1500 launch later this year. For buyers, the lineup creates a clear split: the 5.7-liter offers the strongest towing and payload figures, while the 6.6-liter brings the highest horsepower and torque.