GMC has revealed the all-new 2014 Sierra 1500, which features more connectivity and utility than ever before, as well as a new look and updated powertrains. Under the hood of the new 2014 Sierra you'll find one of three engines: the base engine is a completely new 4.3-liter V-6 based off of the latest V-8 engines. Both a 5.3-liter and 6.2-liter...