Billet Aluminum Carb. Metering Block

The PROFORM Billet Aluminum Carburettor Metering Block (model 67150C) is a precision-engineered fuel management component designed for high-performance Holley 4150-series carburetors. Built from billet aluminum and anodized in distinctive purple, this metering block delivers race-oriented fuel calibration tuning for serious carburetor modifications and engine optimization work.

This primary metering block allows precise control over fuel delivery at cruise and light-load engine conditions—the scenario where factory calibration often wastes fuel or creates driveability issues. The billet aluminum construction offers superior durability compared to cast alternatives, while the purple anodized finish provides both corrosion resistance and easy identification on the dyno or in the engine bay. Gaskets are included, eliminating the need for separate purchases and ensuring proper sealing when installed. At 0.63 lbs and compact dimensions (4.55 x 1.3 x 7 inches), it integrates seamlessly into existing carburetor assemblies without adding bulk or weight.

This metering block is essential for tuners, engine builders, and performance enthusiasts who are dialing in fuel curves on street or race applications. Whether you're refining a freshly ported engine, optimizing a forced-induction setup, or simply upgrading from restrictive OEM carburetor calibration, the ability to swap metering blocks allows rapid A/B testing without full carb removal. The race-oriented design reflects PROFORM's positioning in the high-performance market, where marginal fuel-economy gains and throttle response improvements accumulate into measurable seat-of-the-pants performance.