The 1st Generation Sierra propelled GMC into the 21st century as its best-selling vehicle. With optional LS power, the Sierra can be just as capable at the track as it is the worksite. Whether you're building an all-around street machine, off-roader, or track weapon, Holley has the parts you need to make your dream a reality.

Take control of your vehicle’s power and performance with Handheld Tuners from DiabloSport, Edge, Superchips, and Accel. These plug-and-play devices deliver instant horsepower, torque, and throttle response improvements with user-friendly interfaces and preloaded performance tunes. Ideal for both street and towing applications, handheld programmers let you read and clear DTCs, customize shift points, and fine-tune your driving experience with precision.