Throttle Body Spacer Silverado/Sierra 1500 2WD/4WD (1999-2006 & Classic) Rough CountryRough 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