Carburetor Fuel Inlet Fitting

What Are Carburetor Fuel Inlet Fittings?

Carburetor fuel inlet fittings are the critical connection points between your fuel line and the carburetor's fuel bowl. These fittings thread directly into the carburetor's inlet port and provide a secure, leak-free interface for the fuel line or hose that supplies the carb with a steady stream of gasoline or alcohol-blended fuel. Without a properly matched and correctly sealed inlet fitting, even the finest carburetor can suffer from fuel starvation, hazardous leaks, or inconsistent fuel delivery — all of which directly hurt engine performance and reliability.

The fuel line from the pump attaches to the carburetor's fuel inlet, and the fitting at that junction bears the full burden of sealing pressurized fuel against vibration, heat, and chemical exposure. Any kinks, leaks, or blockages at this connection point can lead to poor fuel delivery and stalling — which is why using the right fitting for your specific carburetor model and fuel line type is essential.

Types of Carburetor Fuel Inlet Fittings

Carburetor inlet fittings come in several distinct styles to match different carburetors and fuel line configurations:

• AN Adapter Fittings – Convert standard carburetor inlet threads (such as 5/8-20, 7/8-20, or 9/16-24) to AN-style (typically -6AN or -8AN) hose ends. These are the go-to choice for performance and racing builds using braided stainless fuel lines.
• Banjo Fittings – A compact, low-profile option that routes fuel in from the side rather than straight in. Popular on Weber, Edelbrock, and Stromberg carbs where clearance is tight.
• Hose Barb Fittings – Thread into the carb's inlet and accept rubber or braided fuel hose, making them an affordable and practical choice for street builds and restorations.
• Dual Feed Fittings – Used primarily on high-performance Holley 4150/4160-style carburetors with dual fuel bowls, allowing a single feed line to supply both bowls simultaneously.
• Adapter & Reducer Fittings – Bridge mismatched thread sizes or connect to non-standard carb inlets, especially useful when upgrading to a different carburetor brand or fuel line diameter.

Key Considerations When Shopping

Selecting the right carburetor inlet fitting starts with knowing your carburetor's inlet thread size and type — common sizes include 5/8-20 (Carter/Edelbrock), 7/8-20 (Holley 4150), 9/16-24 (Holley/Demon), and 1-20 (Rochester). From there, you'll want to match the fitting's outlet to your fuel line type, whether that's an AN hose end, a rubber barb, or a hard steel line with an inverted flare. Material matters too: aluminum and anodized fittings are lightweight and corrosion-resistant for performance builds, while brass and steel fittings are excellent for street restorations. For alcohol or E85 fuels, stainless steel or fuel-compatible aluminum is the safer material choice.

Top Brands in Carburetor Fuel Inlet Fittings

RADIUM Engineering brings its precision motorsports engineering philosophy to the carburetor world, offering uniquely engineered fuel fittings known for their high-quality machining and innovative swiveling designs that simplify routing in tight engine bays. Fragola Performance Systems is a family-owned, Connecticut-based manufacturer that produces a broad range of carburetor inlet fittings in -6AN and -8AN sizes to cover Carter, Edelbrock, Holley, Demon, and Rochester applications — all crafted from aerospace-quality aluminum with an anodized finish. Earl's Performance is one of the most recognized names in AN plumbing, offering carburetor inlet fittings in aluminum and stainless steel across a wide variety of thread sizes and configurations, including banjo hose ends with included hardware for complete installations. Russell Performance rounds out the lineup with a trusted range of carburetor inlet fittings designed to adapt AN-style hose to most carburetor inlets, featuring 37-degree sealing angles for positive, leak-free connections at maximum operating pressure.