Everyone has different needs for their truck. One of the most dramatic changes you can make to a vehicle are the rear ring and pinion gears. Whether you are going for aggressive low end response for performance and towing, you're looking to make your truck a highway cruiser, or you have made a change to your wheel and tire size, we have a ring & pinion for you. Hurst engineering offers gear sets ranging from 3.08 to 4.56 for the GM 12-bolt rear ends to get you exactly where you need to be. "THICK" gear sets indicate that they are compatible with 3.42 and down differentials.