Throttle Body Spacer for 2007 2013 Chevy Silverado GMC Sierra 4.8L 5.3L Amazon.com: MILIPARTS PowerAid Throttle Body Spacer Compatible with Silver Throttle Body Spacer For 99 06 GMC Sierra 1500 2500 3500 4.8 5.3 Chevy Silverado Throttle Bodies & Accessories AmericanTrucks. Rough Country's Throttle Body Spacer helps you get the most out of your 99 06 GM 1500. Engineered with a Spiraling Helix design, our durable, aluminum spacer forces incoming air into a high velocity vortex that aids in a more powerful and efficient fuel combustion process. This process offers improved torque performance and increased fuel economy. Includes an OEM style rubber O Ring Gasket, superior to paper gaskets found in inferior kits. Best of all, this modification is easy to install using a 100 percent bolt on installation process that can be attached in no time! Works with multiple engine sizes: 4. 8L 5. 3L 6. 0L. Features: Easy bolt on installation. Improved torque performance. Increased fuel economy. Notes: Only fits models with 4. 8L, 5. 3L, 6. 0L Vortec engines. Not for use in California pending Air Resource Board Exemption Details: Sold As Each Liter 4. 8 Liter 5. 3 Liter 6. 0 Liter Drive 2WD 4WD Mount Style Bolt On