The aFe Silver Bullet 46-33002 is a throttle body spacer machined from 6061-T6 billet aluminum. It mounts between the intake manifold and the throttle body on the 5.4L V8 in 2004-2010 Ford F-150 trucks. The manufacturer describes a serrated/helix entry that creates turbulence in the air charge just before it enters the engine, and that same entry is meant to avoid the whistle common to plain helix spacers. Buyers choosing between this and a cheaper generic spacer are paying mainly for the billet build and that whistle-reducing entry design, not for guaranteed power. Owners on user forums are generally skeptical that any spacer adds meaningful horsepower on a fuel-injected 5.4L, and several report that the whistle is the most noticeable change. Gains reported by owners vary by truck, so treat this part as a refinement rather than a performance guarantee.
Fitment is the first thing to confirm. The manufacturer lists the spacer for Ford F-150, F-250/F-350 Super Duty and Expedition models from 04-10, plus the Lincoln Mark LT from 06-08, all with the V8-5.4L. Published year breakdowns differ across sources, so verify your specific year and engine against the manufacturer before ordering. The kit includes a gasket and mounting hardware, and the install is a bolt-on job at the throttle body. Search terms this part typically matches include 04-10 F-150 5.4L throttle body spacer, serrated helix TBS no whistle, billet 6061 throttle spacer, and aFe 46-33002 install.
The manufacturer lists the spacer for the 04-10 F-150, F-250/F-350 Super Duty and Expedition, and the Lincoln Mark LT from 06-08, all with the 5.4L V8. Published year breakdowns vary between sources, so confirm your exact model year and engine with the manufacturer before ordering.
The manufacturer states that the serrated/helix entry is designed to eliminate the whistle that helix-only spacers produce. User forums report that many spacers on 5.4L trucks still whistle at part throttle, especially when paired with an aftermarket intake, so results vary.
This is a bolt-on upgrade rather than a modification, so basic hand tools such as sockets and extensions are usually enough. Expect to disconnect the air inlet tube, remove the throttle body fasteners, and set the spacer between two gaskets before reinstalling the throttle body. Check the spacer for any orientation marking before you fit it. Fasteners vary between sources, so test-fit the included bolts into the throttle body and manifold before tightening. Make sure the gaskets seat evenly to avoid vacuum leaks, and reseat the intake tube fully so it does not add noise.
