I just rebuilt my 9" rearend for my '70 Mach1 using Motive Gear's performance 3.89 ring and pinion set and a Detroit True-Trac differential. Below are some pics of the teeth contact patch on the ring gear. Please let me know if this looks good. Motive Grear called for the backlash to be set between .008" and .012". I chose the middle and set the backlash at .010". I used shims to set the pinion dept to the required height. I also used a inch pound torque wrench to set the required pinion bearing pre-load. With all this said and the specs within tolerance, does the contact patch look to be good? Motive Gear shows the contact patch should be dead center of the ring gear tooth. Those guys who have done this before, please let me know what you think. This is my first rebuild, and this contact patch that you see was on my first try. Please let me if you would take the time to see more pics. I can email them to you. Any opinions? Thanks for your time.