General Motors is doubling down on its commitment to internal combustion power with the upcoming sixth-generation small-block V8, slated for production in 2027.
As of April 2026, the specific strategy for the Silverado and Corvette has become clearer through official announcements and credible industry reports.
The Engine Split: 6.6L vs. 6.7L
While it was long speculated that the new “LS6” (Gen VI) architecture would be shared identically across the lineup, GM has reportedly decided on a displacement split to prioritize high-speed performance for the Corvette and low-end utility for its trucks.
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Chevrolet Silverado (6.6-liter V8): * The standard sixth-gen V8 for the Silverado 1500 and GMC Sierra will displace 6.6 liters.
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This is distinct from the current heavy-duty L8T 6.6L cast-iron block; the new Gen VI version is an all-aluminum engine designed for better fuel economy and a 4–6% efficiency improvement.
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Chevrolet Corvette Grand Sport (6.7-liter V8): * Officially unveiled in March 2026, the new Corvette Grand Sport features a stroked version of the Gen VI block displacing 6.7 liters.
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Performance: It produces 393 kW (535 hp) and 705 Nm (520 lb-ft) of torque.
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The “409” Connection: 6.7 liters equates almost exactly to 409 cubic inches, a nostalgic nod to the legendary Chevy big-block of the 1960s.
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Key Technical Details (Gen VI Architecture)
The new engine family maintains the traditional pushrod (overhead valve) design but introduces several modernizations to comply with tightening emissions while delivering more power.
| Feature | Details |
| Material | All-aluminum block and heads with cast-iron cylinder liners. |
| Fuel Delivery | Dual system utilizing both Direct and Port Injection. |
| Bore Spacing | Retains the classic 4.40-inch spacing. |
| Valvetrain | Traditional pushrod, 2 valves per cylinder. |
| AFM/DFM | Advanced Active Fuel Management for cylinder deactivation. |
Manufacturing and Investment
The rollout of these engines is backed by a massive capital injection from General Motors.
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Tonawanda Propulsion (New York): GM is investing $888 million into this Buffalo-area plant specifically to produce the sixth-generation V8 starting in 2027.
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Flint Engine Operations (Michigan): This plant will also be a primary hub for Gen VI production.
Why the Change?
The development follows a difficult period for GM’s current L87 6.2-liter V8, which was subject to a massive global recall in 2024–2025 affecting over 720,000 vehicles (including nearly 10,000 in Australia) due to catastrophic engine failure risks. The Gen VI architecture is seen as a necessary “reset” to provide a more reliable, powerful, and efficient V8 option as competitors like Ram and Toyota move toward turbocharged V6 platforms.
Would you like me to check for the estimated towing capacity of the new 6.6L Silverado or look for the official 0–60 times for the 6.7L Grand Sport?