2007-2010 GMC Sierra 3500HD III (GMT900) Regular Cab Long Box 6.0 V8 (360 Hp) 4WD DRW Automatic

The GMC Sierra 3500HD III, produced from 2007 to 2010, represents the third generation of the Sierra 3500HD heavy-duty pickup truck (GMT900 platform). This particular variant, the Regular Cab Long Box configuration equipped with the 6.0-liter V8 engine producing 360 horsepower and paired with a four-wheel-drive Dual Rear Wheel (DRW) setup and an automatic transmission, was positioned as a work-focused, high-capacity truck aimed at customers needing substantial towing and hauling capabilities. It served as a robust offering within GMC’s lineup, slotting above the lighter-duty Sierra 1500 and 2500HD models, and alongside other 3500HD configurations.

Technical Specifications

INTRODUCTION

The GMC Sierra 3500HD III, specifically this Regular Cab Long Box configuration with the 6.0L V8 and automatic transmission, was a mainstay of GMC’s heavy-duty truck offerings from 2007 through 2010. Built on the GMT900 platform, it represented a significant update over the previous generation, focusing on increased capability, improved refinement, and a more modern interior. The DRW (Dual Rear Wheel) configuration further enhanced its towing and hauling capacity, making it a popular choice for commercial users, farmers, and those requiring serious truck power. This variant was designed for customers who prioritized functionality and durability over luxury or sporty performance.

Powertrain & Engine Architecture

At the heart of this Sierra 3500HD is the Vortec LY6 6.0-liter V8 engine. This engine is a member of the Vortec family, known for its robust construction and reliable performance. The LY6 features a cast iron block and aluminum cylinder heads, utilizing a 9.6:1 compression ratio and a multi-port fuel injection system. The overhead valve (OHV) valvetrain, while traditional, proved to be durable and relatively simple to maintain. The engine produces 360 horsepower at 5400 rpm and 515 Nm (379.84 lb-ft) of torque at 4200 rpm. The Hydra-Matic 6-speed automatic transmission was the sole transmission option for this configuration. This transmission was chosen for its ability to handle the engine’s torque output and provide smooth, reliable shifting under heavy loads. The 4WD system is a traditional part-time system, engaging the front axle when needed for increased traction.

Driving Characteristics

The 6.0L V8 and 6-speed automatic combination in the Sierra 3500HD delivered a capable, if not particularly sporty, driving experience. The emphasis was clearly on work capability. Acceleration was adequate for everyday driving, but the truck truly shined when towing or hauling heavy loads. The automatic transmission’s gear ratios were optimized for pulling power, providing strong low-end torque. Compared to the available Duramax diesel engine option, this gasoline V8 offered less torque and lower fuel economy, but it was significantly less expensive to purchase and maintain. The DRW setup provided exceptional stability when towing, but also made the truck wider and more challenging to maneuver in tight spaces. The ride quality, even with the leaf spring rear suspension, was reasonably comfortable for a heavy-duty truck, though it was noticeably firmer when unloaded.

Equipment & Trim Levels

The Regular Cab configuration of the Sierra 3500HD was typically offered in work truck (WT) and SLE trim levels. The WT trim was very basic, focusing on essential features like air conditioning, a basic audio system, and vinyl upholstery. The SLE trim added features such as cloth upholstery, power windows and locks, and a more comprehensive audio system. Optional extras included a trailer towing package, upgraded audio systems, and various convenience features. Interior materials were durable and functional, prioritizing longevity over luxury. The dashboard layout was straightforward and easy to use, with large, clearly marked controls.

Chassis & Braking

The Sierra 3500HD’s chassis was designed for heavy-duty use. It featured a robust frame and a heavy-duty suspension system. The front suspension utilized an independent torsion bar setup with double wishbones, while the rear suspension employed a traditional leaf spring design. This configuration provided a good balance of ride comfort and load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, with ABS (Anti-lock Braking System) as standard equipment. The DRW configuration provided increased braking capacity and stability, particularly when towing. The steering system was a cone worm with recirculation balls, offering a solid and predictable feel.

Market Reception & Comparison

The GMC Sierra 3500HD with the 6.0L V8 and automatic transmission received generally positive reviews for its capability and durability. Critics praised its strong towing capacity and reliable powertrain. However, it was often criticized for its relatively low fuel economy compared to diesel-powered alternatives. Compared to the Duramax diesel engine option, the 6.0L V8 was more affordable to purchase and maintain, but it offered significantly less torque and fuel efficiency. The Ford Super Duty and Ram 3500 were the Sierra 3500HD’s primary competitors, and each offered similar capabilities and features.

Legacy

The GMT900-generation GMC Sierra 3500HD, and specifically this 6.0L V8/automatic configuration, has proven to be a durable and reliable truck. The Vortec LY6 engine is known for its longevity, and the Hydra-Matic transmission is generally considered to be a robust unit. In the used car market, these trucks remain popular among those seeking a capable and affordable heavy-duty pickup. While fuel economy is a concern, the lower purchase price and relatively simple maintenance requirements make them an attractive option for many buyers. Parts availability is generally good, and the truck’s straightforward design makes it relatively easy to repair. These trucks continue to be seen working on job sites and farms across the country, a testament to their enduring durability and capability.