I usually shoot for .008-.011, and then check the pattern. Have always let the pattern dictate if the backlash was to loose or tight, been lucky so far, and I've done several. How did you set the pinion depth? Pinion depth will effect your pattern as well and how the shims influence backlash adjustment. Alot of times you can get lucky just reusing the pinion shim from the 2.73 to 3.08 gearset when going up to 3.55, 3.73 gearing, but when strech it on out to 4.10, 4.30's the shim often needs changed, just my experience. LOL, isn't it fun working on that 8.8 under the car. It's worth pulling the rear completely out from under the car to work on it in my opinion. Richmond gear has pictures of proper gear pattern on their website.
A forum community dedicated to Ford Mustang owners and enthusiasts. Come join the discussion about performance, production numbers, VIN decoders, modifications, troubleshooting, power adders, DIY tutorials, and more!