Research before you jump in. I understand the pinion should wind up in a certain place to avoid drive-line vibrations, and isn't the exact center. People who used wider C-body rear-ends had to cut both sides. Some found that a Ford 8.8 rear (Explorer?) only needs one side cut, plus get another "short-side" axle and you don't need to cut axles, plus get rear disk brakes. There is a post w/ excellent photos, but don't recall if an early A or 67+.