PickupTrucks.com’s Mike Levine has a First Drive review of two titans of GM’s pickup truck lineup: the 2011 Chevrolet Silverado and the GMC Sierra HD. He took both through the hill country of Maryland, West Virginia and Pennsylvania, and while the trucks look fairly unchanged from the 2010 models, they’re all-new underneath. Find out if the two trucks live up to the high bar set by GM in the past.