After spinning the assembly through several times, a pattern starts to appear where the contact between the ring-and-pinion wears off the paint. When the driver is on the throttle the contact area between the ring-and-pinion will move toward the outside edge of the ring gear. Because of this, you want the pattern to be just inside of center on the ring gear. The pattern you see here is just about perfect. If you need to adjust the wear pattern, you can change the shim thickness between the case and pinion cover.