Just want to chime in; 14' z71 Regular cab (built 7/14) on the GY SRA's and I am pretty sure I have caught a case of the shakes. Truck seemed fine first couple hundred miles, but I now jiggle like a worm anytime I hit smooth pavement at 70+. The issue does not seem too pronounced at lower speeds but I can almost use 70 mph as an on switch for the vibrator. The odd thing is that the shake is not felt in the steering wheel just the frame, either way another fun scheduled dealer visit I suppose.