Overview Are you stuggling for traction, or just have some terrible noise coming from the GM 12-bolt in your truck? Hurst Engineering Limited Slip Differentials offer great traction and strength, but are not overly aggressive for the street. These differentials are 4-spring, composite, clutch-style, limited-slip carriers-with internal gears machined from forged 4320 steel and stronger teeth. These differentials are for GM 12-bolt 30 spline rear ends, and are compatible with 3.73-UP ring & pinion gears. Get rid of that old open differential and upgrade to a limited slip unit! We recommends the use of high grade Non-Synthetic GL-5 gear oil and Yukon LSD additive (or similar) for long life and smooth operation. The use of synthetic oil is not recommended and may result in aggressive or noisy operation Features Fits 3.73 Gear Ratio & Up Fits 12T GM with 30 Spline Axles Composite Clutches for great driveability Feature 4320 chromoly spider gears for ultimate durability Gears are cut to provide the strongest teeth possible in any terrain
