For months we have been fighting a vibration in my deuce 3 window with a 9 inch rear. Not to bore you but we changed, balanced and adjusted everything you would think would cause the problem. Before we took the drastic step of pulling the motor and trans for a trans (5 speed) rebuild the guy working on the car decided to change one more thing so he got a new pinion yoke, changed it and presto no vibration. I talked to the differential manufacturer and he said he'd never seen such a problem?
