A few years ago I changed to a Torsen diff with stock gears. I had a local shop set it up using a new rebuild kit that had a crush sleeve. When I installed it there was a bad whine on acceleration so I brought the car back to shop and they tightened the pinion nut. That worked for a while but in the last couple years there has been a bad growl when hot upon light acceleration and deceleration and getting worse and back lash slop is getting bad. So Im going to pull the diff out and have new gears installed but I want to bring it to an expert for set up and Im also wanting to go with a solid spacer instead of a crush spacer. I have read many post that the Irs is bad on the crush spacer and will eventually cause more back lash and noise. So is there any place in California that expertly can set up these diffs or do I need to send it somewhere? Also what is the recommendation/experiance as to crush spacer vs. solid