The bold Sierra 2500HD, like its Sierra and Silverado brethren, come with a dizzying array of options to choose from. Extensive combinations of cab size, cargo boxes and powertrains make this truck extremely customizable. Three available V-8 engines, including one turbocharged diesel version, are controlled by a six-speed automatic transmission. It can be equipped with an 8-foot cargo box. The Sierra 2500HD is available in regular, extended and crew cab body styles. Four-wheel antilock disc brakes are standard.The GMC Sierra 2500HD carries over from 2007 with little to no changes.