The GMC Sierra 3500HD III, specifically the Crew Cab Long Box configuration with the 6.0-liter V8 engine producing 360 horsepower, represents a significant iteration in GMC’s heavy-duty truck lineage. Produced from 2007 through 2010 (GMT900 platform), this variant was aimed at buyers needing substantial towing and hauling capacity combined with the comfort of a crew cab. It occupied a middle ground in the 3500HD lineup, offering a balance between the base work truck trims and the more luxurious Denali models. This truck was a mainstay for those requiring a robust, American-made pickup for both commercial and personal use.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD III (GMT900) Crew Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) SRW Automatic |
| Start of production | 2007 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.6 kg/Hp, 131.7 Hp/tonne |
| Weight-to-torque ratio | 5.3 kg/Nm, 188.4 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 | 2734 kg, 6027.44 lbs |
| Max. weight | 4445 kg, 9799.55 lbs |
| Max load | 1711 kg, 3772.11 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%) | 5443 kg, 11999.76 lbs |
| Length | 6572 mm, 258.74 in |
| Width including mirrors | 2436 mm, 95.91 in |
| Height | 1931 mm, 76.02 in |
| Wheelbase | 4242 mm, 167.01 in |
| Front track | 1742 mm, 68.58 in |
| Rear (Back) track | 1676 mm, 65.98 in |
| Ride height (ground clearance) | 233 mm, 9.17 in |
| Minimum turning circle (turning diameter) | 16.8 m, 55.12 ft |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| 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 | 265/75 R16; 265/70 R17; 225/75 R17 |
| Wheel rims size | 6.5J x 17; 7J x 16; 7.5J x 17 |
INTRODUCTION
The 2007-2010 GMC Sierra 3500HD Crew Cab Long Box, powered by the 6.0-liter Vortec LY6 V8 and paired with a six-speed Hydra-Matic automatic transmission, was a workhorse designed for demanding tasks. This generation (GMT900) represented a significant step forward in heavy-duty truck design, offering increased capability and a more refined interior compared to its predecessors. The Crew Cab configuration provided ample passenger space, making it suitable for both work crews and families. The Long Box offered a substantial cargo bed, maximizing utility. This particular combination of engine and transmission aimed to provide a balance of power, towing capacity, and everyday drivability.
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. It features a 9.6:1 compression ratio and utilizes multi-port fuel injection for precise fuel delivery. The overhead valve (OHV) valvetrain, while traditional, proved durable and relatively simple to maintain. The engine produces 360 horsepower at 5400 rpm and 515 lb-ft of torque at 4200 rpm.
The six-speed Hydra-Matic 4L80-E automatic transmission was the standard pairing for the 6.0L engine. This transmission is known for its durability and ability to handle high torque loads. The six forward gears allowed for improved fuel economy at highway speeds and provided a wider range of ratios for towing and hauling. The transmission features electronic control for smooth and precise shifting.
Driving Characteristics
The 6.0-liter V8 and six-speed automatic combination delivered a capable, though not particularly sporty, driving experience. Acceleration was adequate for everyday driving, but the truck’s substantial weight (approximately 6,027 lbs) limited its quickness. The automatic transmission shifted smoothly, and the six gears helped keep engine rpm in check during highway cruising. Compared to the available Duramax diesel engine, the 6.0L V8 offered less low-end torque, making it slightly less ideal for extremely heavy towing. However, it was significantly more affordable and simpler to maintain. Compared to the 5.3L V8 offered in the Sierra 2500HD, the 6.0L provided a noticeable increase in power and towing capacity.
Equipment & Trim Levels
The Sierra 3500HD 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. Optional extras included a premium audio system, navigation, heated seats, and a power sunroof. Trim levels varied, but this engine/transmission combo was commonly found in the SLE and SLT trims, offering a step up in features and refinement over the base WT (Work Truck) model.
Chassis & Braking
The Sierra 3500HD featured a robust chassis designed to handle heavy loads. The front suspension utilized an independent torsion bar setup with double wishbones, providing a comfortable ride. The rear suspension employed a traditional leaf spring setup, optimized for load-carrying capacity. Braking duties were handled by ventilated discs at all four corners, providing ample stopping power. An Anti-lock Braking System (ABS) was standard. The truck’s heavy weight and long wheelbase contributed to a stable and predictable handling experience.
Market Reception & Comparison
The 6.0-liter V8-powered Sierra 3500HD was generally well-received by critics and buyers alike. It offered a compelling alternative to the diesel-powered models, particularly for those who didn’t require the ultimate in towing capacity or who preferred the lower maintenance costs of a gasoline engine. Fuel economy was typical for a heavy-duty truck, averaging around 14-16 mpg in combined driving. Reliability was generally good, although some owners reported issues with the Active Fuel Management (AFM) system, which deactivated cylinders under light load to improve fuel economy. Compared to Ford’s Super Duty and Ram’s heavy-duty trucks, the Sierra 3500HD offered a competitive combination of capability, comfort, and value.
Legacy
The 6.0-liter Vortec LY6 engine and 4L80-E transmission combination proved to be a durable and reliable powertrain. Today, these trucks are readily available on the used market at relatively affordable prices. While they may not offer the fuel efficiency of newer trucks, they remain a capable and practical choice for those needing a heavy-duty pickup. The AFM system, while sometimes problematic, can often be disabled to improve long-term reliability. Overall, the 2007-2010 GMC Sierra 3500HD Crew Cab Long Box with the 6.0-liter V8 represents a solid and dependable work truck that continues to serve owners well.
