Fuel System Fittings

Fuel System Fittings: the small parts that keep fuel where it belongs

Fuel system fittings are the adapters, hose ends and port fittings that join your pump, lines, rails and regulator into one leak-free circuit. They convert between AN flare sizes, thread standards and quick-disconnect ends so components from different brands actually seal together. Anyone building or upgrading a fuel setup ends up needing them, because a pump outlet or a hose end rarely matches the next part in the chain straight out of the box. Get the fittings right and the system holds pressure; get them wrong and you chase weeps and pressure drops.

These are working parts. A hose end has to bite and swivel on the line without cutting into it, and a port adapter has to match both the thread pitch and the sealing style - O-ring boss on one side, male flare on the other - so nothing backs off under vibration.

What ThreePiece stocks

There are 12 fuel system fittings in stock right now, spanning three brands: Aeromotive (8 of the 12), DeatschWerks (3) and Fleece Performance (1). Current pricing runs from $34 to $100, which is the live range for what is on the shelf rather than a fixed promise.

Concrete examples show the spread. The Aeromotive Spur Gear Pump Outlet AN-12 Port sits at the top of the range, and the Aeromotive AN-12 O-Ring Boss to AN-12 Male Flare Adapter is a straight thread-to-flare converter. On the DeatschWerks side, the 6AN 90-degree PTFE swivel hose end and the 6AN to 3/8in EFI quick-disconnect cover braided-line and factory-quick-connect jobs. The Fleece Performance 1/2in CP3 Feed Fitting is the single diesel-pump feed option here.

How to choose

Start with the size and sealing style at each end. AN-12 parts like the Aeromotive port and adapter are for larger flow paths; the DeatschWerks 6AN parts are for smaller feed and return lines. Decide whether you are running braided line - which wants a swivel hose end - or tying into a factory EFI quick-connect, which is what the 6AN-to-3/8in disconnect is for. If you are on a diesel CP3 pump, the Fleece feed fitting is the specific answer. The price gap between a $34 feed fitting and a $100 pump outlet reflects size and function, not a quality tier - buy the part that matches your thread and flow, not the most expensive one.

What else you need with it

Fittings are one link in the chain. Pair them with the right Fuel Pumps to move the volume, and browse the broader Fittings and Adapters categories when you need a thread combination that is not here. While the engine is apart it is worth checking Gasket Kits. All of these sit under the wider Engine Components section.

Fitment and ordering

None of these 12 fittings list vehicle-specific fitment, so match them by port size, thread and end style rather than by make. If you are unsure which end you are joining, call fitment help at 813-535-5801 or reach us through contact us. Every order ships free, and Affirm and Katapult financing is available at checkout.

Fuel System Fittings: the small parts that keep fuel where it belongs

Fuel system fittings are the adapters, hose ends and port fittings that join your pump, lines, rails and regulator into one leak-free circuit. They convert between AN flare sizes, thread standards and quick-disconnect ends so components from different brands actually seal together. Anyone building or upgrading a fuel setup ends up needing them, because a pump outlet or a hose end rarely matches the next part in the chain straight out of the box. Get the fittings right and the system holds pressure; get them wrong and you chase weeps and pressure drops.

These are working parts. A hose end has to bite and swivel on the line without cutting into it, and a port adapter has to match both the thread pitch and the sealing style - O-ring boss on one side, male flare on the other - so nothing backs off under vibration.

What ThreePiece stocks

There are 12 fuel system fittings in stock right now, spanning three brands: Aeromotive (8 of the 12), DeatschWerks (3) and Fleece Performance (1). Current pricing runs from $34 to $100, which is the live range for what is on the shelf rather than a fixed promise.

Concrete examples show the spread. The Aeromotive Spur Gear Pump Outlet AN-12 Port sits at the top of the range, and the Aeromotive AN-12 O-Ring Boss to AN-12 Male Flare Adapter is a straight thread-to-flare converter. On the DeatschWerks side, the 6AN 90-degree PTFE swivel hose end and the 6AN to 3/8in EFI quick-disconnect cover braided-line and factory-quick-connect jobs. The Fleece Performance 1/2in CP3 Feed Fitting is the single diesel-pump feed option here.

How to choose

Start with the size and sealing style at each end. AN-12 parts like the Aeromotive port and adapter are for larger flow paths; the DeatschWerks 6AN parts are for smaller feed and return lines. Decide whether you are running braided line - which wants a swivel hose end - or tying into a factory EFI quick-connect, which is what the 6AN-to-3/8in disconnect is for. If you are on a diesel CP3 pump, the Fleece feed fitting is the specific answer. The price gap between a $34 feed fitting and a $100 pump outlet reflects size and function, not a quality tier - buy the part that matches your thread and flow, not the most expensive one.

What else you need with it

Fittings are one link in the chain. Pair them with the right Fuel Pumps to move the volume, and browse the broader Fittings and Adapters categories when you need a thread combination that is not here. While the engine is apart it is worth checking Gasket Kits. All of these sit under the wider Engine Components section.

Fitment and ordering

None of these 12 fittings list vehicle-specific fitment, so match them by port size, thread and end style rather than by make. If you are unsure which end you are joining, call fitment help at 813-535-5801 or reach us through contact us. Every order ships free, and Affirm and Katapult financing is available at checkout.