The Chevrolet Silverado 3500 HD II (GMT900) Extended Cab Long Box, equipped with the 6.0-liter V8 engine producing 360 horsepower and paired with a four-wheel-drive Dual Rear Wheel (DRW) automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2007 to 2010, this variant occupied a crucial position in the Silverado 3500 HD lineup, catering to owners requiring substantial towing and hauling capabilities without sacrificing everyday usability. It was part of the GMT900 generation, a substantial redesign of Chevrolet’s heavy-duty trucks focused on increased strength, improved interior refinement, and enhanced safety features.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD II (GMT900) Extended Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) 4WD DRW Automatic |
| Start of production | 2007 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 8.2 kg/Hp, 121.7 Hp/tonne |
| Weight-to-torque ratio | 5.7 kg/Nm, 174.1 Nm/tonne |
| Power | 360 Hp @ 5400 rpm |
| Power per litre | 60.3 Hp/l |
| Torque | 515 Nm @ 4200 rpm, 379.84 lb.-ft. @ 4200 rpm |
| Maximum engine speed | 6000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Vortec LY6 |
| Engine displacement | 5967 cm3, 364.13 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 101.6 mm, 4 in. |
| Piston Stroke | 92 mm, 3.62 in. |
| Compression ratio | 9.6:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 5.7 l, 6.02 US qt | 5.02 UK qt |
| Coolant | 15.5 l, 16.38 US qt | 13.64 UK qt |
| Kerb Weight | 2958 kg, 6521.27 lbs |
| Max. weight | 5171 kg, 11400.1 lbs |
| Max load | 2213 kg, 4878.83 lbs |
| Trunk (boot) space – maximum | 2170 l, 76.63 cu. ft |
| Fuel tank capacity | 129 l, 34.08 US gal | 28.38 UK gal |
| Permitted trailer load with brakes (12%) | 5307 kg, 11699.93 lbs |
| Length | 6330 mm, 249.21 in |
| Width including mirrors | 2436 mm, 95.91 in |
| Height | 1927 mm, 75.87 in |
| Wheelbase | 4001 mm, 157.52 in |
| Front track | 1742 mm, 68.58 in |
| Rear (Back) track | 1897 mm, 74.69 in |
| Ride height (ground clearance) | 233 mm, 9.17 in |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels permanently, and the front wheels are driven through an electrically or mechanically operated clutch if necessary. |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 6 gears, automatic transmission Hydra-Matic |
| Front suspension | Independent torsion bar, double wishbone |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 325×38 mm |
| Rear brakes | Ventilated discs, 325×30 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 225/75 R17 |
| Wheel rims size | 6.5J x 17 |
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD II lies the Vortec LY6 6.0-liter V8 engine. This engine, a member of Chevrolet’s Vortec family, is renowned for its robust construction and ample low-end torque. The LY6 utilizes a cast iron block and aluminum cylinder heads, contributing to its durability. It features a 9.6:1 compression ratio and a multi-port fuel injection system, delivering a balance of power and efficiency. The overhead valve (OHV) valvetrain, while a more traditional design, proved reliable and cost-effective. The engine’s 360 horsepower and 380 lb-ft of torque were channeled through a Hydra-Matic 6-speed automatic transmission. This transmission was chosen for its ability to handle the engine’s output and provide smooth, predictable shifts, crucial for towing and hauling heavy loads. The 4WD system employed a shift-on-the-fly mechanism, allowing drivers to easily switch between two-wheel drive and four-wheel drive depending on road conditions.
Driving Characteristics
The 6.0L V8 and 6-speed automatic combination in the Silverado 3500 HD II delivered a driving experience geared towards work and capability. While not a performance-oriented setup, the engine provided sufficient power for everyday driving and demanding tasks. The automatic transmission’s gear ratios were optimized for towing, with lower gears providing ample torque for starting and maintaining speed with heavy loads. Compared to the available diesel options (like the Duramax), this gasoline engine offered a more responsive feel at lower RPMs, but lacked the diesel’s superior fuel economy and ultimate towing capacity. Compared to a manual transmission equipped Silverado, the automatic offered convenience, especially in stop-and-go traffic, but sacrificed some driver control and potentially a slight amount of fuel efficiency.
Equipment & Trim Levels
The Silverado 3500 HD II Extended Cab Long Box with the 6.0L V8 typically came standard with features like air conditioning, power windows and locks, and a basic audio system. The Extended Cab configuration provided additional rear seating and storage space compared to the regular cab models. Trim levels varied, but generally included options for upgraded cloth or leather upholstery, premium audio systems, and convenience features like power-adjustable seats and a tilt steering wheel. Popular options included a trailer brake controller, a navigation system, and various towing packages designed to maximize the truck’s capabilities.
Chassis & Braking
The Silverado 3500 HD II featured a robust chassis designed to withstand heavy loads. The front suspension utilized an independent torsion bar setup with double wishbones, providing a comfortable ride and good handling. The rear suspension employed a traditional leaf spring design, known for its durability and load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) was standard, enhancing safety and control during emergency braking situations. The Dual Rear Wheel configuration significantly increased the truck’s stability and load-carrying capacity, making it ideal for hauling large trailers or heavy equipment.
Market Reception & Comparison
The Silverado 3500 HD II with the 6.0L V8 and automatic transmission was generally well-received by truck buyers seeking a capable and reliable workhorse. Critics praised its strong engine, comfortable ride, and spacious interior. However, it often faced criticism for its fuel economy, which was lower than that of diesel-powered competitors. Compared to the Duramax diesel engine, the 6.0L V8 offered a lower initial cost but higher long-term operating expenses due to fuel consumption. It positioned itself as a strong alternative for those who didn’t require the ultimate towing capacity of a diesel but still needed a heavy-duty truck for demanding tasks.
Legacy
The Chevrolet Silverado 3500 HD II (GMT900) with the 6.0L V8 remains a popular choice in the used truck market today. The Vortec LY6 engine is known for its durability and relatively simple maintenance requirements. While some owners have reported issues with oil consumption and active fuel management (AFM) systems, these problems are often manageable with proper maintenance and repairs. The truck’s robust chassis and capable drivetrain ensure that it can continue to provide years of reliable service for those seeking a heavy-duty work truck. Its affordability and readily available parts make it a practical and appealing option for buyers on a budget.
