Rob, any change in the gear noise now that you have driven it more? I have a very minor gear noise and I was considering trying the lucas additive. Mine is an 8 3/4 open diff.
Check your passenger side rear axle adjustable end play, that should be .012 ths.
If it is way more than .012 ths you may have more problems coming your way. First thing that wears out is the center cross pin in the diff carrier when it starts to go on the open diffs.
On a good note, adjust the end play on the adjustable passenger side axle back to factory specs. That may help to tighten things up a bit and reduce the noise.
Lots of times the main carrier bearings start to get wore enough to let the ring gear to start moving away from the pinion gear a few thousands, changing the wear pattern and creating a gear whine.
New bearings will help bring it back into spec, along with readjusting the ring gear backlash (side to side end play).
