EVIL ENERGY AN6 Male Flare to 1/4" NPSM Adapter for 4L80E — Aluminum Silver, 2-Pack (Short & Long)

EVIL ENERGY AN6 male flare to 1/4" NPSM adapters are CNC-machined aluminum fittings that convert AN6 (9/16"-18 UNF) transmission cooler lines to 1/4"-18 NPSM ports for 4L80E-type transmissions.

These two purpose-built adapters let you connect common 6AN hoses to the front and rear transmission ports found on many GM 4L80E and related engines. Machined from 6061-T6 aluminum and anodized for corrosion resistance, each kit includes a short and a long length to suit differing port depths. They seal with a 37° AN seat on the AN side and a parallel NPSM thread on the vehicle side, creating a reliable interface for oil and other compatible liquids.

Will these fittings work on my 4L80E transmission?

Yes — the adapters were designed to fit the transmission cooler ports used on a wide range of GM transmissions and compatible engines. Verify your vehicle uses 1/4"-18 NPSM female ports and that your hose uses AN6 male flare fittings before ordering.

• Compatible models include 4L80E and many GM engines listed in product details (LS1, LQ4, LM7, etc.).
• Works with 1/4"-18 NPSM female cooler ports and standard AN6 hoses.
• Includes both short (front port) and long (rear port) lengths to match port depth.
• Intended for fluid lines (oil, fuel, coolant where applicable); confirm system specifications.

How do I install these AN6 to NPSM adapters?

Installation is straightforward with basic hand tools. Thread the NPSM end into the transmission port, then attach the AN6 hose to the 37° seat; use the hex flats to tighten to manufacturer-recommended torque to avoid over-tightening.

• Clean mating surfaces and apply thread sealant if required by the vehicle service manual.
• Hand-start threads to avoid cross-threading, then tighten using a wrench on the hex flats.
• Ensure proper hose orientation and routing to prevent stress or chafing on the fitting.
• Inspect for leaks at operating temperature and re-torque if necessary.

What materials and durability can I expect from these adapters?

The fittings are CNC machined from 6061-T6 aluminum and receive an anodized finish to resist corrosion and fluid exposure. Their hex design makes installation easier while the 37° AN seat provides a metal-to-metal seal on the AN side.

• 6061-T6 aluminum body for strength and reduced weight.
• Anodized surface treatment protects against oxidation and fluids.
• Precision CNC machining ensures consistent thread fit and sealing angles.
• Suitable for oil, fuel, and many liquid mediums—confirm compatibility for your application.

Who is this for? These EVIL ENERGY AN6-to-1/4" NPSM transmission fittings are aimed at mechanics, DIY enthusiasts, and performance builders who need a reliable adapter between AN6 hoses and GM transmission cooler ports. If you’re converting cooler lines, repairing damaged fittings, or customizing a transmission plumbing setup on vehicles using 4L80E-style ports, this two-piece kit (short and long versions) offers a practical, corrosion-resistant solution that simplifies hose fitting and ensures a proper seat.