The real question is this, How Much Sag? You can take a good look at the "Sag Indicators". They tell you in an instance! If there is only one or two Alignment Shims, the Frame has Sagged over the years! The weight of the vehicle on each wheel is a form of leverage. It bends metal. That is just the way it is! This happens to Big, Huge, Perimeter Frames and more often than not Differential Tubes!
