Street Differentials

Posi, limited slip, Traction-Lok, or whatever your favorite brand calls it is how your rear axle provide equal traction to both tires, and trust us, you’ll need it! So, read all about posi units and their benefits here in our guide.

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.

Learn about the power behind the G-body platform and the steps to upgrade a 7.5" bolt rear end to a 8.5" to withstand high horsepower. See how to change the differential fluid and install new gaskets.

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.

Read up on GM 10 bolt ring and pinion installation instructions. Follow along as our employee Zach installs a GM 10 bolt rebuild kit from Motive Gear.

How to determine the quick change R&P ratio without opening up the rear in street cars with quick changes, sprint cars, modifieds, late models and GOTRA cars.

Take your crate motor racing to the next level with these tricks and tips that won't get you in hot water with tech officials!

Steve provides a step-by-step guide to install the Speedway Motors GM 10-Bolt Polished Finned Aluminum Rear End Cover.

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

A full floating rear end is not just for dedicated track cars anymore. Many high horsepower street cars will be well suited to make the move to a Grand National style full floating axle. Read on to see why.