Y-Block Fitting - 6an to 2 x -4an

The Y-Block Fitting - 6AN to 2 x -4AN (Aeromotive MPN 15671) is a critical manifold component for any serious fuel system upgrade or custom engine build. This adapter allows you to split a single -6AN fuel line into two separate -4AN branches, making it indispensable when distributing fuel pressure to dual carburetors, secondary fuel rails, or split-feed fuel systems on performance and racing applications. Whether you're running a fuel-injected swap, a carburetor conversion, or a complex multi-stage fuel delivery setup, this Y-block fitting ensures clean, efficient flow distribution while maintaining system integrity under high-flow conditions.

Manufactured by Aeromotive, a trusted name in professional fuel system components, this Y-block fitting uses precision-engineered aluminum construction to handle sustained AN fuel line pressures without leakage or degradation. The 6AN inlet accepts industry-standard -6 Aeroquip or equivalent hose, while dual -4AN outlets provide stable, balanced fuel distribution to multiple destinations. The compact design (2.65 x 1.3 x 3.75 inches) fits tight engine bays and custom chassis layouts, and the minimal weight (0.07 lbs) ensures no impact on vehicle dynamics. Proper sizing and quality brass sealing surfaces prevent cavitation and ensure consistent fuel pressure across all branches during acceleration, deceleration, and sustained throttle events.

This fitting serves mechanics, fabricators, and enthusiasts building modified carbureted engines, fuel-injected LS swaps, classic hot rods, and street/strip race vehicles. Installation requires AN-compatible hose and matching -6 to -4 adapters; verify your fuel line sizing before ordering to ensure proper system flow rating and pressure stability. Pair this Y-block with quality fuel regulators, lines, and filters for optimal performance and reliability in high-output applications where fuel distribution precision directly impacts drivability and safety.