In order to get it right the first time since we're building everything from scratch, we decided to bolt the cab down and get EXACT measurements for the body mounts. We started by measuring out the back of the cab. With it perfectly even on both sides we welded a bolt to the frame table running up through the cab mount holes. Once all four corners were perfect we tightened them all down. This process takes a couple people (thanks Sean) to ensure the cab doesn't move.