Well, I had time to pull the rear cover today and count gear teeth. Turns out that the drivetrain shop installed 4.10s in the front, but installed 4.56s in the rear. That just isn't going to work out!
Figure I'll give the drivetrain shop a chance to make things right, but since it has been at least 6 years since the work was done I expect I'll be finding another shop to install 4.10s in this rear axle
