Selecting the right differential for your rearend build is an important decision that will be with you for a very long time - if you get it right.

Below are short, not-too-technical, overviews of some of the most frequently asked about differential options for Hot Rods, Muscle Cars, and Muscle Trucks. //

Detroit Truetrac - Helical-gear limited-slip (worm differential) is the modern replacement for the classic clutch-type posi. //

Trac-Lok/Posi-Trac – Clutch-type limited-slip (Posi), offered as original equipment in many GM and Ford performance cars, these units rely on clutches (friction plates) to transfer power to the wheels. //

Detroit Locker - Automatic "ratcheting-style" differential is known for its reliability, rugged construction, and fully-locked performance on any surface. When power (torque) is applied in either forward or reverse directions, the unit locks both axles together like a spool. When coasting or rolling through a corner (no torque applied), the unequal speed of the inside and outside wheels causes the unit to unlock momentarily, before abruptly locking when power is applied.