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

The GMC Sierra 3500HD III, specifically the Crew Cab Long Box configuration with the 6.0-liter V8 engine producing 360 horsepower and paired with a four-wheel drive system and automatic transmission, was a prominent offering in the heavy-duty pickup truck segment from 2007 to 2010. This iteration, built on the GMT900 platform, represented GMC’s third generation of heavy-duty trucks, designed to cater to buyers needing substantial towing and hauling capabilities alongside passenger comfort. It occupied a sweet spot in the lineup, offering a balance between capability and everyday usability, appealing to both commercial users and private owners requiring a robust truck.

Technical Specifications

INTRODUCTION

The GMC Sierra 3500HD III, in its Crew Cab Long Box configuration with the 6.0L V8 and automatic transmission, was produced from 2007 through 2010. This model year represented a significant refresh of GMC’s heavy-duty lineup, building upon the foundation of the GMT900 platform. The Sierra 3500HD was positioned as a workhorse, designed for demanding tasks like towing large trailers, hauling heavy payloads, and providing a comfortable cabin for long distances. The Crew Cab configuration offered increased rear passenger space, making it suitable for families or work crews. This particular variant, with its 6.0-liter engine and automatic transmission, aimed to provide a balance of power, usability, and convenience.

Powertrain & Engine Architecture

At the heart of this Sierra 3500HD lies 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 utilizes a cast iron block and aluminum cylinder heads, contributing to its durability. It features a 9.6:1 compression ratio and utilizes multi-port fuel injection for precise fuel delivery. The overhead valve (OHV) valvetrain, while a more traditional design, proved to be dependable and relatively easy to maintain. The engine produces 360 horsepower at 5400 rpm and 515 Nm (379.84 lb-ft) of torque at 4200 rpm.

The engine is mated to a Hydra-Matic 6-speed automatic transmission. This transmission was designed to handle the high torque output of the 6.0L V8 and provide smooth, efficient shifting. The automatic transmission was a key selling point for buyers who preferred the convenience of not having to manually shift gears, especially when towing or hauling heavy loads. The transmission’s gear ratios were optimized for both towing and fuel economy, offering a balance between performance and efficiency.

Driving Characteristics

The 6.0L V8 and 6-speed automatic combination in the Sierra 3500HD delivered a capable, though not particularly sporty, driving experience. The engine provided ample torque for towing and hauling, making it well-suited for demanding tasks. However, compared to the available Duramax diesel engine, the 6.0L V8 offered less low-end grunt. Acceleration was adequate, but not brisk. The automatic transmission shifted smoothly and predictably, contributing to a comfortable ride. The 6-speed transmission helped keep the engine in its optimal power band during acceleration and highway cruising. Compared to manual transmission equipped models, the automatic offered less driver control but greater convenience.

Equipment & Trim Levels

The Sierra 3500HD III in this configuration typically came standard with features like air conditioning, power windows and locks, and a basic audio system. The Crew Cab configuration offered a spacious interior with seating for five passengers. Upholstery was typically cloth, though leather was available as an option. Higher trim levels, such as the SLT and Denali, added features like leather upholstery, heated seats, a premium audio system, and chrome exterior trim. Optional extras included a navigation system, a sunroof, and a rear-seat entertainment system.

Chassis & Braking

The Sierra 3500HD III featured a robust chassis designed to handle heavy loads. The front suspension utilized an independent torsion bar and double wishbone setup, providing a comfortable ride and good handling. The rear suspension employed a rigid axle with leaf springs, offering excellent load-carrying capacity. Braking duties were handled by ventilated discs on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) was standard equipment. The rear axle was a single rear wheel (SRW) configuration, common for this class of truck.

Market Reception & Comparison

The GMC Sierra 3500HD III with the 6.0L V8 and automatic transmission received generally positive reviews. Critics praised its towing and hauling capabilities, comfortable ride, and spacious interior. However, it was often noted that the 6.0L V8 lacked the low-end torque of the available Duramax diesel engine. Fuel economy was also a concern, as the 6.0L V8 was not as fuel-efficient as the diesel option. Compared to the 6.6L Duramax diesel, the 6.0L V8 was a more affordable option, appealing to buyers who didn’t require the ultimate in towing capacity or fuel efficiency. The 1.8L and 1.9L TDI versions of the European models were not comparable due to the different market segment and vehicle class.

Legacy

The Vortec 6.0L LY6 engine, when properly maintained, has proven to be a relatively reliable powertrain. Common issues include oil consumption and potential head gasket failures, but these are often preventable with regular maintenance. Today, these Sierra 3500HDs are readily available on the used market at relatively affordable prices. They remain popular choices for buyers seeking a capable and durable heavy-duty truck. The GMT900 platform is known for its longevity, and many examples are still in service today, testament to its robust design and construction.