GM X-Body Differentials

GM’s 10-bolt rear axle has been around since the 1960s, here’s how to determine if your junkyard find is worth taking home

Need a little help Identifying GM Body Styles 1964-1972? Click Here!

Learn what gear oils do for your differential and how to choose the best gear lubricant for your application's needs

Decode, ID, and upgrade your GM 12-bolt rear end. Learn axle specs, gear ratios, and best performance parts upgrades.

A brief overview of the steps Speedway Motors takes to ensure you get a quality differential.

Learn about GM alternator identification in our guide. We cover GM 3 wire alternators, 1 wire alternators, and externally regulated so you know what to choose.