Truck bed dimensions for a GMC Sierra depend on the version. The full long bed is 8 ft. The short bed is 6.5 ft. Slight variations exist depending on the model. Note: the Sierra line and the Chevrolet Silverado are basically the same. The difference is that the Sierra has more luxury options.
The hybrid 4WD is 73.9 in (1,877 mm) high, while the hybrid 2WD is 71.2 in (1,808 mm). Other versions are 77 in (1,956 mm) or 74 in (1,880 mm) high. All versions are 78.5 in (1,994 mm) wide. The length is 230.2 in (5,847 mm) for the hybrid. Other versions are 246 in (6,248 mm), 227 in (5,766 mm) or 203 in (5,156 mm) long. The wheelbase is 143.5 in (3,645 mm) / 133 in (3,378 mm) / 119 in (3,023 mm).
GMT900 Heavy Duty
This version is 76 in (1,930 mm) high. It is 80 in (2,032 mm) wide. With the towing mirrors it is 95.9 in (2,436 mm). Versions for military applications were also produced, making the truck bed dimensions for a GMC Sierra even more diverse.
This is a fortified variant of the Silverado/Sierra line. It comes in the 3500, 2500HD and 1500HD models. Introduced in 2001, the 1500HD has a Vortec 6000 V8 with 300 hp (224 kW) at 5200 rpm. The 3500 has the same transmission and engine as the 2500HD.
The hybrid 4WD is 73.7 in (1,872 mm) while the crew version is 73.8 in (1,875 mm). The regular and extended are 73.9 in (1,877 mm) high. The length varies too. The hybrid is 229.9 in (5,839 mm), the extended & crew are 230.2 in (5,847 mm) and the regular is 205.6 in (5,222 mm). The wheelbase is 143.5 in (3,645 mm) for the extended & crew. For regular it is 119 in (3,023 mm).
The GMT900 came out during the 2006/2007 production years. The engines and power have been enhanced. The suspension, frame, interior and exterior was redesigned. The appearance was inspired by the Chevrolet Colorado pickups. Fuel economy is improved thanks to the tighter panel gaps. The aerodynamics has also been enhanced due to the windshields which are raked steeply. In 2007, these models were re-labeled “classic”.
The truck bed dimensions for a GMC Sierra may become more varied in the future. This is due to several upcoming models. For this reason, the truck beds may be lengthened or shortened.