Adapter Fitting -6 x LT -1 5/16 Return

The Adapter Fitting -6 x LT -1 5/16 Return from FRAGOLA is a precision fuel line adapter engineered for high-performance automotive fuel systems. This straight adapter fitting bridges 6 AN male connections to 5/16 inch SAE female quick-disconnect couplings, making it essential for custom fuel system builds, carburetor conversions, and aftermarket fuel pump installations. Mechanics and engine builders rely on these adapters to create flexible, leak-free fuel delivery pathways that accommodate non-standard component spacing and layout requirements in modified vehicles.

Constructed from aluminum and finished in black anodized coating, this adapter resists corrosion and integrates seamlessly into under-hood environments. The straight configuration minimizes pressure drops and turbulence compared to 90-degree fittings, preserving fuel flow efficiency in return-line circuits where backpressure regulation matters. The 6 AN male thread (0.75-16 UN specification) mates reliably with standard braided stainless steel fuel hose or rigid aluminum tubing, while the 5/16 SAE female quick-disconnect end accepts factory and aftermarket fuel line couplers. Weighing just 0.05 lbs, this compact fitting (1.25 x 1 x 4.15 inches) introduces zero bulk to engine bay layouts.

This adapter excels in EFI conversions on classic and vintage engines, turbocharged engine fuel system upgrades, and dual-fuel setups requiring secondary return lines. Drag racers, street rod builders, and tuners use these fittings to adapt modern fuel injector rail returns to factory tank filler neck couplers or aftermarket surge tank inlets. Installation requires standard SAE wrench sizes and basic thread-seal tape or fuel-grade thread sealant. Verify quick-disconnect coupler compatibility before purchase, as SAE female couplers vary slightly between manufacturers—confirm your existing connector type matches the 5/16 inch standard fitting size for a trouble-free installation.