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Vehicle Info Needed650 CFM High Performance 4150 Carburetor Main Body Mechanical Secondary Design
Ships on 09/08/2026
Lowest Price Guarantee- Technical Note: Main body does not retain vacuum advance port in original metering block.
Specs
- Air Bleed Material: Brass
- Booster Style: Down-Leg Boosters
- CFM: 650 CFM
- Discharge Nozzle Size (Primary / Secondary): .031 in. / .031 in.
- Fuel: Gasoline
- Idle (Outer) Air Bleed Size: 73 / 73
- Material: Aluminum
- Finish: Natural
- Primary Jet Size: 86 / 93
- Mechanical Secondaries
- Secondary Outer Air Bleeds: 36
- Includes Air Bleeds, Fuel Bowl Gaskets and Screws
Proform's High Performance Carburetor Main Body is a 100% new, direct replacement component for your wore out or leaking carb main body. The race inspired design helps add up to 25-50 horsepower. It is packed with features like smooth radius venturis, down-leg or annular boosters, adjustable screw-in air bleeds, air horn and choke plate delete. This main body is developed to get maximum air flow that easily turns your street carb into a high performance race-design carb. This high performance swap is an easy installation utilizing your existing metering blocks, fuel bowls and base plate. Comes complete with instructions, all necessary non-stick replacement gaskets and a high performance jet kit. This main body does not retain vacuum advance port in original metering block.
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Features:- 100% New Components, Not re-built
- All Aluminum Construction (excluding p/n 778-67203, Zinc Construction)
- Smooth Radius Venturis
- Choke Horn Deleted
- High Performance Down-Leg or Annular Boosters
- Adjustable Screw-In Air Bleeds
- Easy Swap, Direct Replacement
- Includes Instructions, Non-Stick Gaskets and Jet Kit
Unlock serious performance potential with the Proform High Performance Carburetor Main Body — a smart upgrade designed to deliver real horsepower gains and effortless installation. Built with 100% new components, this main body is engineered to transform your existing carburetor into a high-flow, race-ready setup.
This upgrade replaces your traditional carburetor body with a feature-rich design that includes smooth radius venturis, high-performance down-leg or annular boosters, and adjustable screw-in air bleeds. These enhancements eliminate airflow restrictions like choke towers and air horns, enabling substantial airflow improvements. In fact, many builders report horsepower gains of 25–50 with this swap.
Installation is remarkably straightforward. Because it uses your existing metering blocks, fuel bowls, and base plate, it’s a quick upgrade — typically involving just 14 screws and taking less than 30 minutes. Whether you're prepping a street machine, track car, or high-output cruiser, this unit delivers increased throttle response and enhanced top-end flow without requiring a full carb replacement.
For builders looking to optimize fuel delivery and airflow, this carburetor body is tailored for just that. If you’re serious about eliminating bottlenecks and achieving stronger engine performance, this Carburetor Main Body is a smart choice. Upgrade with confidence, install quickly, and experience noticeably sharper acceleration and stronger overall efficiency under load.
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