64 cuda 7 1/4 rear

The rear is apart right now, will send some pics of the ring gear. The last few times we test drove it we believe it is moving a little metal. The first time the pinion depth was set to 2.062 as per mfg. spec. that shim thickness was .092, backlash was set at .008 according to pattern from there pinion shims were changed to .091 then .087 then .095 then .096 then .094 Each time the backlash was set between .007 and .009 and had noise every time. .094 seemed to be the least noise. Two times we had a bad pattern not driven,can't remember which times. Original housing had std carrier and we switched it to posi-traction, the first two shim changes had that carrier, we found the carrier was warped .005 Then we changed it back to the std carrier, it was much better only out by .001, we used GL 5 80-90 gear lube. On the last time we used 50% that and 50% lucas petroleum stabilizer with no change. brgs were replaced twice. Noise definitely coming from ring and pinion