Im about to change my standard diff centre, crownwheel & pinion for a 3.45 lsd from a donor XR6. The problem being that the XR6 had been fitted with 3.23 gears for highway driving and the 3.45 gears are separate. I was wondering if the 3.45 LSD needs pinion shims and if so, what thickness. I dont want to get it together and have a heap of backlash.