GM LY6 Engine

Specifications

The GM LY6 engine is a 6.0-liter Gen IV V8 iron-block engine produced from 2007 to 2010, specifically designed for heavy-duty trucks and commercial vans that demand durability, torque, and long service life. Rated at approximately 361–385 horsepower and 385–400 lb-ft of torque, the LY6 delivers strong pulling power across the rev range, making it well-suited for towing, hauling, and off-road use. One of its key advantages is Variable Valve Timing (VVT), which adjusts camshaft timing on the fly to improve low-end torque, mid-range power, and overall efficiency. The engine features a 9.6:1 compression ratio, a 4.00-inch bore, and a 3.622-inch stroke, giving it a balanced design that favors both strength and performance.  

Its rectangular-port aluminum cylinder heads, similar to LS3 heads, offer excellent airflow and significantly enhance its responsiveness to upgrades such as performance camshafts, intakes, headers, and tuning. Built around a rugged cast-iron block, the LY6 is capable of handling high horsepower levels with proper supporting modifications, which has made it a popular choice for engine swaps, boosted applications, and budget-friendly high-performance builds. Combining modern Gen IV technology with proven LS architecture, the LY6 remains highly regarded for its reliability, versatility, and impressive power potential.   

Compatible Models

Chevrolet Silverado 2500HD / 3500HD (2007–2009)

In the Chevrolet Silverado 2500HD and 3500HD, the 6.0L LY6 was engineered to deliver dependable power for demanding work applications. Designed for towing heavy trailers, hauling payloads, and long-duty cycles, the LY6 provided strong low- and mid-range torque that made these trucks reliable jobsite and fleet performers. Its iron-block durability and VVT-equipped Gen IV design ensured consistent performance under load, while still offering solid aftermarket potential for owners looking to increase power without sacrificing reliability.   

GMC Sierra 2500HD / 3500HD (2007–2009)

The GMC Sierra 2500HD and 3500HD paired the LY6 engine with GMC’s upscale heavy-duty platform, balancing refinement with serious capability. The engine’s robust torque output made it ideal for towing and commercial use, while Variable Valve Timing improved drivability and efficiency across varying conditions. Known for longevity and strength, the LY6 helped cement the Sierra HD lineup as a dependable option for contractors, fleets, and enthusiasts who value durability with room for performance upgrades.

Chevrolet Suburban 2500 (2007–2009)

In the Chevrolet Suburban 2500, the LY6 offered heavy-duty capability in a full-size SUV package. This combination made it especially popular for large families, towing-focused users, and commercial applications that required both passenger space and serious pulling power. The engine’s smooth torque delivery, strong iron-block construction, and modern Gen IV features allowed the Suburban 2500 to confidently handle trailers, boats, and long highway trips with minimal strain. 

GMC Yukon XL 2500 (2007–2009)

The GMC Yukon XL 2500 utilized the LY6 to provide premium comfort backed by true heavy-duty performance. With its strong torque curve and VVT-enhanced efficiency, the LY6 allowed the Yukon XL 2500 to excel at towing while maintaining smooth, predictable power delivery. This setup made it a favorite among users who needed luxury, space, and serious capability, all supported by an engine known for reliability and high horsepower potential with aftermarket modifications.    

Frequently Asked Questions