The aFe Silver Bullet throttle body spacer (part 46-38006) is a billet aluminum spacer that the manufacturer describes as a serrated/helix entry design. It mounts between the factory throttle body and the intake manifold on the 4.7L V8 in 2000-2004 Toyota Tundra and 2001-2004 Sequoia trucks. The manufacturer says the entry profile creates turbulence and eliminates the annoying whistle found in other helix only throttle spacers, which is the main reason to choose this over a cheaper, plainer spacer.
Set realistic expectations before buying. The horsepower, torque, and mileage gains are the manufacturer's claims, and enthusiast opinion is split. One Tundra forum thread argues that spacers don't add any benefit on a fuel injected engine, and another notes that throttle body spacers don't do anything on the Tundra except add sound. Treat this as an airflow and sound-tuning part rather than a guaranteed power adder, and pair it with intake or exhaust work if measurable gains matter to you.
Fitment follows the manufacturer's application list for the 4.7L V8, which covers Tundra, Sequoia, 4Runner, Land Cruiser and Lexus LX 470 applications. Because the spacer uses all factory mounting locations, it bolts on without custom brackets. Installation is a DIY-friendly, bolt-on job. Searchers looking for 4.7 Tundra throttle body spacer whistle elimination, billet TBS for 2000-2004 Tundra, or Sequoia 4.7 intake spacer fitment will find the key details below.
The manufacturer lists the Tundra 4.7L V8 for 2000-2004 models. Trim-level coverage varies between sources, so confirm your specific truck with the manufacturer before ordering.
The manufacturer states that the serrated/helix entry is designed to eliminate the whistle common to helix-only spacers. Results can still vary with your intake setup.
User forums are mixed. Some owners report no measurable benefit, and one forum thread cites a test that found no gain on the Tundra. Expect sound and airflow changes more than guaranteed horsepower.
This is a manageable weekend-level job with basic hand tools. Per the manufacturer's install sheets for related Silver Bullet spacers, the process starts by loosening the clamps between the factory intake tube, the throttle body, and the factory airbox. Then keep the four factory throttle body screws in case the vehicle needs to be returned to stock. The spacer goes between the intake manifold and throttle body, with the "TOP" engraving facing up, and the supplied gasket sits between the spacer and the throttle body. Check that the butterfly valve moves freely by hand, since the spacer must not interfere with it. Sockets in the 8mm and 10mm range are typical for this family, but confirm against the sheet packed with your kit. Finally, retighten all bolts and clamps after 100 miles of driving.
