GMC's pride and joy, the Sierra 1500, is entering a new generation with the 2027 model year.The full-size pickup sports a new exterior design and gets a totally overhauled interior, which now features an actuating center screen.The 2027 Sierra adds GM's new 5.7-liter and 6.6-liter V-8s, though nearly everything else below the truck's bodywork is carried over from the previous generation.