I pre-determined that I was sitting on a very flat (no crown) piece of driveway and used a rafter square to see the difference from vertical at the top of the wheel and the bottom of the wheel. When the square was touching the bottom, I measure 3/8" gap at the top. Pretty much what I was shooting for. I started with 15/16" and 5/8" after installing the springs and my adjustable arms. I drove it a little bit and waited a week to let them all settle. And they did!