Throttle Body Spacer for GMC Sierra (2003-2007) 4.8L 5.3L 6.0L 6.2L 8.1L

Billet Throttle Body Spacer for 2003-2007 GMC Sierra

What it Does: Lengthens the intake plenum track between the throttle body and intake manifold to enhance air charge velocity and improve low-end throttle response.

The Stock Sierra Plenum Volume Limitation

Factory Vortec intake manifolds on GMT800 trucks suffer from abrupt runner transitions and limited pre-runner plenum volume. Under sudden throttle opening, the intake tract experiences localized boundary-layer separation and turbulent low-velocity air right past the butterfly valve. This dead volume delays throttle tip-in response and restricts instantaneous cylinder filling, which is especially noticeable under heavy hauling or low-RPM acceleration.

The Engineering Solution

This throttle body spacer is precision CNC-machined from aircraft-grade 6061-T6 billet aluminum, engineered with an open-bore, helical-profile air path that stabilizes intake air column velocity before entering the runner split. The increased volume between the throttle plate and plenum floor improves cylinder scavenging and eliminates turbulence at off-idle transitions. Finished in a corrosion-resistant anodized coating, the spacer includes 304 stainless steel hardware to prevent thread galling and ensure a leak-free seal without throwing lean condition trouble codes.

Technical Specifications

Compatibility

• 2003-2007 GMC Sierra 1500 (4.8L V8, 5.3L V8, 6.0L V8)
• 2003-2007 GMC Sierra 1500 HD (6.0L V8)
• 2003-2007 GMC Sierra 2500 / 2500 HD (6.0L V8, 8.1L V8)
• 2003-2007 GMC Sierra 3500 / 3500 HD (6.0L V8, 8.1L V8)
• 2007 GMC Sierra 1500 Denali (6.2L V8)

The GMC Heavy-Duty Standard

Engineered to handle severe duty cycles, this solid billet spacer withstands sustained manifold vacuum, engine-bay heat soak, and heavy towing strain without warping or introducing unmetered air leaks.