Ive had the car up around 90 mph a few times lately and I seem to be getting a decent vibration, but when I let go of the gas it stops. The vibrating seems to happen when I hit it down...if I cruise up to 80...85...90 it doesnt seem to have the vibration. I did some searching and I read the "turn it 180* degrees solution" and I read the GM service annoucement. What should I do? Should I just swing by the Chevy dealer and see what they say? Its only 5 minuntes away, but Ive never taken my car to the dealer. I am not really sure what the "turn 180 degrees means." Also, I just installed a moser 12 bolt with 4.10's, bmr lca, tq arm and panhard rod. I did the search so I am really looking for what my best option is and any other feedback about this situation. I wouldnt be so worried right now but I want to get my car solid before I go to the track for the first time, I dont want to go to the track and have something blow up my first time at the track.