Banjo 4an > 3/8in

The Banjo 4AN > 3/8in fitting from Earls is an essential adapter for any serious fuel system build or hydraulic line configuration where size reduction is required. This banjo-style connector allows you to step down from a larger 4AN (AN4) line to a smaller 3/8-inch port, making it ideal for connecting to fuel filters, carburetors, regulators, or engine bay components with tighter port configurations. Whether you're restoring a classic muscle car, upgrading a street machine's fuel delivery system, or fabricating a custom hydraulic setup, this adapter ensures proper flow with zero leaks.

Earls banjo fittings are engineered from aluminum or steel construction with precision-machined sealing surfaces that create a reliable connection without adapter complexity. The banjo design incorporates a bolt-through eyelet that accepts a single bolt with two 0-ring seals—one on each side of the banjo body—to prevent fluid weeping at the junction. This design is favored by engine builders and fuel system specialists because it handles moderate pressure without thread-stripping risk and allows quick disconnect by simply removing the bolt. The 4AN to 3/8-inch step-down ratio is commonly used when transitioning from modern AN braided hose systems to OEM-style threaded ports found on classic carburetors or mechanical fuel regulators.

Technicians and DIY enthusiasts benefit most from this adapter when retrofitting fuel systems, converting carbureted engines to fuel injection, or building custom fuel cell installations where port sizing varies across components. Installation requires a single bolt (typically AN3 or AN4 fastener) and the proper O-ring seals sized for 4AN applications. Always verify the receiving port's thread type—whether it accepts the banjo's bolt configuration—and ensure all sealing surfaces are clean before assembly to prevent leaks under fuel pressure. This compact, lightweight fitting integrates seamlessly into tight engine bays and works with both gasoline and compatible fuels.