Pinion Depth on 8.75 741 case

Changing preload will not change ANYTHING but preload. Once the bearing is seated in the race, it cannot go any further. All you can do is tighten the nut down more and apply more preload. The pinion ain't goin anywhere. It certainly wouldn't have an affect on backlash. That's the adjustment for the ring gear. .008" is fine. I would leave it alone.