Make for the hills with new Sierra Throttle Body Spacers. Throttle Body Spacers increase the gap between your air intake and engine block. Blaze your own trail with these Sierra Throttle Body Spacers. Air is added to the combustion cycle more efficiently with Throttle Body Spacers. Promote your truck to the head of the class with upgraded Sierra Throttle Body Spacers. Throttle Body Spacers add horsepower. Get the added benefit of better mpg with a Throttle Body Spacer.