The Chevrolet shop manuals on every thing else from a Chevette on up was pretty much as I posted,and never less than 10.I thought it was strange at the time.I've only had one 12 bolt though and I started with new stuff. I used to do quite a few rear assemblies when I worked at Chevrolet dealerships and in the aaftermarket,but I'm no expert I just know enough to be dangerous.