The aFe Silver Bullet Throttle Body Spacer (part 46-34018) is a bolt-on aluminum spacer for the GM L5 inline-five in the Chevrolet Colorado and GMC Canyon. It mounts between the throttle body and the intake manifold. The manufacturer says it is CNC-machined from 6061-T6 billet aluminum and uses a serrated/helix entry. That entry is designed to churn incoming air and reduce the intake whistle that helix-only spacers can produce, and the manufacturer holds a patent on the design. The spacer also lengthens the intake track, which the manufacturer says raises intake air speed for a sharper throttle response.
Stock throttle bodies sit directly on the manifold, so this spacer is a low-cost way to add volume between the throttle plate and the cylinders. Owners on user forums are split on how much seat-of-the-pants difference it makes. Some report quicker throttle response, while others consider throttle body spacers a waste of money on fuel-injected trucks. The manufacturer does not publish a horsepower or torque figure for this application, so set expectations accordingly. For a Colorado or Canyon 3.5L or 3.7L L5 owner building a cold-air or throttle-response setup, this is a no-drill option that uses the factory mounting points and includes a gasket for a leak-free seal. Search terms: aFe Silver Bullet L5 throttle body spacer, Colorado 3.7L throttle body spacer, Canyon 3.5L intake whistle fix.
The manufacturer lists this spacer for the L5 3.5L in 2004-2006 and the L5 3.7L in 2007-2012 Colorado and Canyon models. Confirm your engine and model year with the manufacturer before ordering, because listings differ on the exact year breakdown.
No. The manufacturer states that the part is not CARB exempt and is not available for sale or use in California.
The manufacturer says this spacer uses the factory mounting locations, so no drilling is required. Based on aFe install sheets for other Silver Bullet spacers, the job generally involves removing the engine cover and intake tube, disconnecting the throttle body harness, and unbolting the four throttle body fasteners. The spacer goes between the throttle body and the manifold with the supplied gasket between the spacer and throttle body. Orient the spacer with its engraved "AIR IN" or "TOP" side facing the throttle body, as those sheets specify, then reinstall the fasteners with the longer bolts provided. Torque the bolts to the value on the install sheet for your vehicle, and recheck all clamps before starting the engine. Common gotchas include letting the throttle body hang by its harness and mixing up the spacer's orientation. Keep the factory hardware in case you need to return the vehicle to stock.
