6AN to 4AN Reducer Black Male Male

The REDHORSE PERFORMANCE 6AN to 4AN reducer black male male adapter is an essential flow-control fitting for modern performance fuel and hydraulic systems. This straight adapter bridges two different AN-sized lines, allowing mechanics and enthusiasts to downsize from a larger 6AN line to a smaller 4AN component with zero flow restriction at the transition. Built for high-pressure applications, this fitting solves compatibility challenges when upgrading fuel systems, cooling loops, or brake lines where existing components don't match standard sizes.

Constructed from lightweight aluminum and finished in black anodize, the 6AN to 4AN reducer delivers durability and corrosion resistance in under-hood and interior environments. The straight-port design eliminates turbulence and pressure drop that occurs with elbow configurations, maintaining system integrity across high-flow fuel injection, turbo cooling, and hydraulic brake applications. Black anodizing provides both aesthetic consistency with modern engine bay builds and a protective oxide layer that extends fitting life in salt-air and moisture-prone conditions. The male-to-male threading ensures secure sealing with standard AN fittings, crimped hose ends, and block adapters without requiring additional components.

This reducer is ideal for custom fuel system builds, carbureted-to-EFI conversions, and engine swaps where line sizing transitions are unavoidable. Street rod builders, drag racers, and turbo-charged platform enthusiasts rely on REDHORSE fittings to maintain pressure ratings and flow consistency during system modifications. Installation is straightforward—thread the 6AN port into your larger fuel rail, pump outlet, or cooler, then connect 4AN hose or components to the smaller outlet port. Weighing just 0.07 lbs and measuring a compact 2.8 x 1.1 x 3.8 inches, it fits tight engine bays and custom plumbing runs without interference.