Dodge Modern Muscle Differentials

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

A new print and digital magazine about all things street rodding and more, brought to you by some familiar names.

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

A short article explaining the main differences between open and limited slip 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

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

Tim M. continues his quest to breathe life into a tired old 241 Dodge baby Hemi. This round, Tim dives into giving the 241 an electrifying makeover, courtesy of a Pertonix electronic ignition system, all cleverly hidden inside existing hardware.

Lucas P. explains how to choose the correct part for a Ford 9" third member build in order to achieve a bulletproof rear. You will find specific recommended parts to use from Speedway Motors.

Need help with rear end identification for your muscle car or hot rod? Learn how to identify 9-inch Ford housings and how to measure your axles with our diagrams.

This resource contains a transmission pan shape ID chart and other tips to help with identifying GM transmissions.