Millions of Chevrolet vehicles were built and sold in the 1960s and 1970s, and the great majority of those were rear-wheel-drive models with differentials known as 10-bolts or 12-bolts. In Chevy Differentials: How to Rebuild the 10- and 12-Bolt, author Jefferson Bryant walks you through the entire process of procuring, evaluating, and rebuilding the perfect differential for your GM application.