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

The GMC Sierra 3500HD III, specifically the Regular Cab Long Box configuration with the 6.0-liter V8 engine producing 360 horsepower, was a mainstay of GMC’s heavy-duty truck lineup from 2007 to 2010. This generation (GMT900) represented a significant step forward in capability and refinement for GMC, aiming to provide a robust work truck with a degree of comfort previously unseen in the 3500HD class. Positioned as a work-focused trim, it served as the entry point into the 3500HD range, offering substantial towing and payload capacity for commercial users and those with demanding hauling needs. It sat below the more luxurious Denali trim and offered a more affordable alternative to the diesel-powered variants.

Technical Specifications

INTRODUCTION

The GMC Sierra 3500HD III, produced between 2007 and 2010, represented the third generation of GMC’s heavy-duty truck platform (GMT900). This iteration built upon the foundation laid by its predecessors, offering increased towing capacity, improved interior comfort, and a more refined driving experience. The Regular Cab Long Box configuration, paired with the 6.0-liter Vortec LY6 V8 engine and a four-speed Hydra-Matic automatic transmission, was specifically geared towards buyers prioritizing work capability and affordability. It was a popular choice for fleet vehicles, farmers, and individuals needing a robust truck for demanding tasks. The “SRW” designation indicates a Single Rear Wheel configuration, distinguishing it from Dual Rear Wheel (DRW) models designed for even heavier loads.

Powertrain & Engine Architecture

The heart of this Sierra 3500HD is the 6.0-liter (5967 cc) Vortec LY6 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, contributing to its durability. It utilizes a traditional overhead valve (OHV) valvetrain with two valves per cylinder. Fuel delivery is managed by a multi-port fuel injection system, providing precise fuel metering for optimal combustion. 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 four-speed Hydra-Matic 4L80-E automatic transmission. This transmission is a heavy-duty unit designed to handle the substantial torque output of the 6.0L V8 and the demands of heavy towing. While not as technologically advanced as some newer automatic transmissions, the 4L80-E is known for its durability and simplicity. The gear ratios are optimized for towing and hauling, prioritizing low-end torque over outright acceleration.

Driving Characteristics

The 6.0L V8 and 4L80-E automatic combination delivers a solid, if not particularly exhilarating, driving experience. Acceleration is adequate for everyday driving, but the truck’s substantial weight (2564 kg / 5652.65 lbs) is noticeable. The four-speed automatic, while reliable, lacks the refinement and efficiency of more modern transmissions with more gears. The gear ratios are spaced to maximize towing performance, meaning the engine often operates at higher rpm during highway cruising. Compared to the available Duramax diesel engine, the 6.0L V8 offers significantly less torque, resulting in a lower maximum towing capacity. However, it provides a smoother and quieter driving experience than the diesel, and is generally less expensive to maintain.

Equipment & Trim Levels

The base Regular Cab 3500HD trim typically included features such as air conditioning, a basic AM/FM radio, vinyl upholstery, and manual windows and locks. Optional extras included power windows and locks, a CD player, upgraded cloth or leather upholstery, and a towing package. The interior was functional and durable, designed to withstand the rigors of work truck use. The dashboard layout was straightforward and easy to use, with large, clearly marked controls.

Chassis & Braking

The Sierra 3500HD III utilizes a body-on-frame construction, providing a robust and durable platform. The front suspension consists of an independent torsion bar setup with double wishbones, offering a comfortable ride and good handling. The rear suspension employs a traditional leaf spring setup, designed to handle heavy loads. Braking duties are handled by ventilated disc brakes on all four wheels, with ABS (Anti-lock Braking System) as standard equipment. The truck’s substantial weight necessitates a robust braking system to ensure safe and controlled stopping power.

Market Reception & Comparison

The 6.0L V8-powered Sierra 3500HD was generally well-received by critics and buyers seeking a capable and affordable heavy-duty truck. It offered a compelling alternative to the more expensive diesel-powered models, particularly for those who didn’t require the diesel’s maximum towing capacity. Fuel economy was a common criticism, as the 6.0L V8 is not particularly fuel-efficient. However, the engine’s relatively simple design and readily available parts contribute to lower maintenance costs compared to the Duramax diesel. Compared to competitors like the Ford Super Duty and Ram Heavy Duty, the Sierra 3500HD offered a similar level of capability and refinement.

Legacy

The 6.0L Vortec LY6 engine, when properly maintained, has proven to be a durable and reliable powertrain. While some issues, such as Active Fuel Management (AFM) problems, have been reported, these can often be addressed with relatively simple repairs. Today, the 2007-2010 GMC Sierra 3500HD with the 6.0L V8 remains a popular choice in the used truck market, particularly for buyers seeking a capable and affordable work truck. Its robust construction, readily available parts, and relatively simple maintenance requirements make it a practical and dependable option for those needing a heavy-duty truck for hauling and towing.