GM’s New 5.7- and 6.6-Liter V8s Turn Silverado and Sierra Into Sleepers

The Chevy Silverado and GMC Sierra add more powerful 5.7- and 6.6-liter V8s this year, while the Corvette keeps its distinct 6.7-liter version.
September 21, 2026
GM’s New 5.7- and 6.6-Liter V8s Turn Silverado and Sierra Into Sleepers

Chevy will launch a new Corvette Grand Sport for 2027. If you’ve been following that news, you’ll know the GS was the first GM vehicle to receive the automaker’s all-new sixth-generation small-block V8. Now we’ve seen the versions that matter most to GM’s best-selling pickups.

The new L76 and L78 V8s are headed to the upcoming model-year Chevrolet Silverado 1500 and GMC Sierra 1500, and both substantially outperform the engines they replace. That should benefit truck owners whether they’re towing a boat, hauling a bed full of timber, or looking to surprise a hot hatch away from a stoplight.

Both engines retain the Gen V’s familiar 4.4-inch (112 mm) bore spacing, along with a single-cam, overhead-valve design that dates back to the first small-block introduced in 1955. However, compression ratios and throttle-body diameters increase over last year’s specifications, as does displacement. The new V8s measure a retro-friendly 350 and 400 cubic inches.

Towing Demon

GM’s New 5.7- and 6.6-Liter V8s Turn Silverado and Sierra Into Sleepers

The entry-level L76 is a 5.7-liter V8 replacing the 5.3-liter EcoTec3. Output rises from 355 to 402 hp (360-408 PS), while torque increases from 383 lb-ft (519 Nm) to 428 lb-ft (580 Nm). Those figures are strong on their own, and GM says the Silverado’s 13,700-lb (6,200 kg) tow rating exceeds that of every other truck in its class. Buyers seeking more power can select the L78.

The larger engine displaces 6.6 liters, versus 6.2 liters for its predecessor and 6.7 liters for the 535-hp (542 PS) LS6 in the MY27 Corvette. The Corvette engine uses a slightly longer stroke. Compared with the old 6.2-liter’s 420 hp (426 PS) and 460 lb-ft (624 Nm), the new 6.6-liter produces 481 hp (488 PS) and 501 lb-ft (679 Nm).

TurboMax Also Gains Horses

GM’s New 5.7- and 6.6-Liter V8s Turn Silverado and Sierra Into Sleepers

GM also upgraded the entry-level 2.7-liter four-cylinder TurboMax, adding 40 hp (41 PS) and 25 lb-ft (34 Nm) for totals of 350 hp (355 PS) and 455 lb-ft (617 Nm). The 3.0-liter Duramax turbo-diesel retains its 305 hp (309 PS) and 495 lb-ft (671 Nm), but GM says revisions to components including the pistons, turbo vanes, and injector improve performance and reliability. The top speeds of the V8-powered pickups remain unknown, though the 6.6-liter appears to have the ingredients for a genuinely stealthy truck.

Payload and maximum towing capacity vary by vehicle configuration, trim, and available packages.

James Walker
WRITTEN BY
James Walker
James follows the latest vehicles, automotive technology and major updates from carmakers around the world.
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