Two new V8 engines, which will help power General Motors’ next-generation light-duty pickup portfolio in the 2027 Chevrolet Silverado 1500 and GMC Sierra 1500, provide full-size pickup truck customers with increased capability and performance from GM’s sixth-generation Small Block architecture.
The new L76 5.7L and L78 6.6L V8 engines bring GM’s next-generation Small Block architecture to its light-duty truck lineup, joining the LS6 6.7L V8 developed for the 2027 Corvette Stingray, Grand Sport and Grand Sport X. As with the LS6, which brought the 409-cubic-inch displacement back to the Small Block engine family, the L76 and L78 herald the return of the 350 and 400 cubic-inch displacements, respectively.
For decades, the Small Block architecture has been adapted for production vehicles, endurance racing, marine propulsion and customer-built performance applications. GM Powered Solutions applies Small Block engineering to marine-specific applications, while Chevrolet Performance continues to offer a broad portfolio of Small Block, LS/LT and racing crate engines.
More Displacement, More Power
All-new Gen-6 6.6L V8 continues down assembly line at GM's Flint Engine Operations.General Motors
The layout of the new engines begins with an architectural element shared with more than 100 million Small Block engines dating back to 1955: cylinder bore centers spaced at 4.40-inch intervals.
To generate more horsepower and torque from the new light-duty truck V8s, GM engineers applied several key enablers:
- Increased displacement from 5.3L and 6.2L to 5.7L (350 cubic inches) and 6.6L (400 cubic inches), respectively, by increasing piston stroke 6 mm
- Higher compression ratio for more efficient combustion
- More airflow via larger throttle diameters
- New intake manifolds with tuned runners to manage the additional airflow
The 5.7L V8 delivers 402 horsepower and 428 lb.-ft. of torque. No other truck in the segment tows more than GM's light-duty trucks, and the Silverado 1500 achieves a maximum available tow rating of 13,700 pounds when properly equipped.
The 6.6L V8 offers 481 horsepower and 501 lb.-ft. of torque.
“These new V8 engines advance GM’s legendary Small Block architecture with greater capability, more advanced technology and the strength of GM’s manufacturing footprint behind them,” Small Block engines Chief Engineer Tom Bishop said. “They’re engineered to provide truck customers the confidence and performance they expect from a GM V8.”
Additional sixth-generation features include:
- A dual-fuel system that combines direct injection and port fuel injection for expanded operation in optimal power, efficiency and emissions windows
- New lubrication system featuring a continuously variable oil pump, on-engine oil cooler and reworked oil feed locations for additional oil pressure consistency
Both engines are developed for the everyday demands of full-size trucks, from towing and hauling to commuting and off-road driving. By the time the next-generation trucks arrive at dealerships later this year, GM development teams expect to complete more than 1.5 million miles (2.4 million km) of real-world, on-road validation.
A powertrain portfolio built around customer choice
All-new Gen-6 6.6L V8 in process of assembly at GM's Flint Engine Operations.General Motors
The new V8 engines join the Enhanced TurboMax and available Dyuramax 3.0L Turbo-Diesel offerings in a four-engine lineup for the Next-Generation Silverado 1500 and Sierra 1500.
Next-generation light-duty powertrain quick reference
General Motors
An enhanced TurboMax with best-in-class standard torque adds 40 horsepower and 25 lb.-ft. of torque, improving performance, drivability and noise and vibration refinements. Updates include a new turbocharger, upgraded fuel injection system, improved active thermal management and redesigned pistons. Now paired with a 10-speed automatic transmission, the engine is designed to deliver smoother shifts, stronger power delivery and improved towing performance.
The segment-exclusive Duramax 3.0L Turbo-Diesel returns with 305 horsepower and 495 lb.-ft. of torque, continuing to offer smooth, quiet operation and strong low-end torque for towing, long-distance driving and everyday use. Updates include revised DEF level indicators and additional target improvements, including piston, turbo vane, next-generation NOx sensor, sealing and fuel injector corrosion-protection updates.
All engines for GM’s 2027 light-duty truck lineup are paired with a 10-speed automatic transmission. A new 34 gallons (129 liter) fuel tank is available for the 5.7L and 6.6L V8s, and when paired with the Duramax 3.0L Turbo-Diesel, offers a highway driving range of over 900 miles.
Investing in North American manufacturing
Production of the new 5.7L and 6.6L V8 engines will be performed by the teams at GM’s Flint Engine Operations, Tonawanda Propulsion and St. Catharines Propulsion plants.
GM has previously announced significant North American manufacturing investments to support next-generation truck and V8 production, as part of a $9 billion investment across U.S. manufacturing, including $888 million at Tonawanda Propulsion in New York for sixth-generation V8 engines for full-size trucks and SUVs.
In Canada, GM is investing over $493 million at St. Catharines Propulsion to support production of its sixth-generation V8 engines, which power full-size trucks and SUVs. GM has also announced additional investments in facilities supporting related truck manufacturing and 10-speed transmission capacity.
The new 5.7L and 6.6L V8 engines will be available with the launch of the next-generation Chevrolet Silverado 1500 and GMC Sierra 1500 later this year. Additional vehicle information, including MSRP, will be shared in future updates.
