EVIL ENERGY 6AN Male to Dual Quick-Disconnect EFI Fuel Rail Adapter — 3/8" & 5/16", Aluminum, 1500 psi

EVIL ENERGY's 6AN male to dual quick-disconnect female EFI fuel rail fitting converts a 6AN 37° flare connection to 3/8" and 5/16" quick-disconnect fuel lines in a compact, aluminum alloy component.

This compact adapter is engineered for high-pressure fuel systems commonly found on EFI engines, LS swaps and aftermarket fuel rails. Machined from 6061-T6 aluminum with a 37° flare sealing surface, it accepts a 6AN (9/16-18UNF) male thread and provides two female quick-disconnect ports sized for 3/8" and 5/16" inner-diameter lines. Rated to 1500 psi and built to work across a broad temperature range, it bridges AN fittings and factory-style quick-disconnect fuel hoses in retrofit and custom installations.

How does the 6AN thread interface with factory fuel lines?

The adapter uses a 6AN (9/16-18UNF) male flare thread to mate with standard AN-style fuel components. Internally it presents two quick-disconnect female ports that accept 3/8" and 5/16" fuel hoses typically used on EFI rails and sensors.

• 6AN male thread: 9/16-18UNF thread pitch
• Female quick-disconnect IDs: 3/8" and 5/16"
• 37° flare sealing angle to match AN fittings
• Direct, tool-friendly installation for retrofit work

Is this fitting durable enough for high-pressure EFI systems?

Yes — the body is CNC-machined from 6061-T6 aluminum, a material commonly used in fuel-system components for strength-to-weight balance. The design includes a metal-to-metal 37° flare seal and a plastic spring lock in the quick-disconnect mechanism for reliable retention without excessive weight.

• Working pressure rating: 1500 psi
• Operating temperature range: -40°F to 250°F
• Aluminum alloy 6061-T6 construction for corrosion resistance
• Plastic spring lock on quick-disconnect for positive engagement

Which applications and vehicles is this adapter suited for?

The adapter is designed for fuel rails, aftermarket EFI conversions, LS swaps, transmission cooler feed/return lines and installations that require mixing AN-style fittings with quick-disconnect factory hoses or sensors. It’s ideal where space is limited and a compact conversion is needed.

• EFI fuel rails and aftermarket carburetion conversion lines
• LS engine swaps and custom fuel-system plumbing
• Fuel sensors, return lines, and transmission cooler feeds
• Retrofit projects bridging AN fittings to OE-style quick-disconnect hoses

How do I install and maintain this quick-disconnect fuel fitting?

Installation requires standard AN wrenches and verifying proper orientation of the quick-disconnect ports. Inspect seals and the plastic spring lock periodically; replace any damaged hoses or worn quick-disconnect collars to maintain system integrity.

• Tighten 6AN male to mating AN flare using correct torque practices
• Push fuel hoses into quick-disconnect ports until the spring lock engages
• Check for leaks at assembly and after initial run-in
• Replace plastic spring lock or O-rings if damaged or worn

Who is this for: This EVIL ENERGY adapter is for mechanics, fabricators, and enthusiasts building or modifying EFI fuel systems who need a compact conversion from a 6AN flare connection to factory-style 3/8" and 5/16" quick-disconnect lines. It suits anyone working on LS swaps, aftermarket fuel rails, or custom plumbing where a reliable, pressure-rated aluminum fitting is required.