3.90's
 

So, I got my 3.90's installed the other day, and I, and the shop were not happy with the install. For some reason, nothing really wanted to line up right. First they tried it with the stock shims, and he said that it wasn't lining up right. So, he started using the shims from the install kit. He thought he had finally got it lined up right, and it was making great contact, just how it should. But, it whines so bad. So, they told me to drive it a couple days, thinking maybe there was a burr on the gear, or something, and bring it back today (Tuesday), and they'll tear it apart again and see what's going on. Anyone have any ideas on what it could be? They do lots of gear installs, and they actually did another Camaro just a few weeks ago that came out perfectly. So, they do know what they're doing. Is there something more tricky about 3.90's than other gears, or could it just be a bad gearset maybe? Any thoughts and suggestions would be greatly appreciated.

doesn't sound like they know what theyre doing to me. Find another shop.