Well I only went 1/8th inch more vibes are a little better, but still there from 20-40 MPH. I guess I'll try some bigger shims on the rear. Anyone know what degree shims come with 4" Superlift springs, and how much more I should go to increase for the 1" zerorate. Thats where the vibes came from I am pretty sure. /forums/images/graemlins/waytogo.gif