This GM LS Non-Return Style Fuel System Plumbing Kit were made using the same fuel system we run in our own LS swaps, rock crawlers, race cars, and custom chassis builds. Specifically for returnless LS fuel rails,this kit regulates pressure at the tank and removes the need for a return line from the engine bay.

The system is built for off-road reliability using a Walbro 255 LPH fuel pump and Fragola -6 AN nylon race hose and fittings. By integrating the filter/regulator assembly, the kit maintains consistent fuel pressure while simplifying plumbing and reducing clutter at the engine.

Included Components:

• (6) -6 AN Straight Fittings
• (3) -6 AN 90 Fittings
• (1) 3/8" Quick Disconnect to -6 AN Straight
• (1) 3/8" Quick Disconnect to -6 AN 90
• (1) 5/16" Quick Disconnect to -6 AN
• (1) 3/8" Female to -6 AN Fitting
• (1) Filter/Regulator Assembly (Returnless Style)
• (1) Walbro 255 LPH Fuel Pump with Sleeve & Clamps
• (2) Pump Fittings to -6 AN
• (20 ft) -6 AN Premium Nylon Race Hose

Specifications

• Fuel System Type: Non-Return (Returnless LS Fuel Rail)
• Application: GM LS Engines & LS Swaps
• Hose Size: -6 AN
• Hose Length: 20 Feet
• Fuel Pump Flow Rating: 255 Liters Per Hour
• Regulator Style: Filter/Regulator Combination Unit
• Fittings: Fragola Performance
• Hose Type: Fragola Nylon Race Hose

Fitment

• Designed for GM LS engines using non-return (returnless) fuel rails
• Ideal for:
  • LS swaps
  • Tube chassis rock crawlers
  • Ultra4 and race builds
  • Custom off-road rigs

For traditional return-style LS fuel systems, check out the WODLS Return Fuel System Kit.

Tech Insight

1.What is a non-return fuel system for an LS engine?

A non-return fuel system, often called a returnless fuel system, sends fuel from the tank directly to the engine without requiring a dedicated return line from the LS fuel rails. Fuel pressure is regulated near the fuel tank using a filter and fuel pressure regulator assembly, simplifying plumbing and reducing the number of fuel lines that need to be routed through the vehicle.

2. What LS fuel rails does this kit work with?

This kit is designed specifically for factory-style GM LS fuel rails that use a returnless configuration. These LS fuel rails only require a supply line to the engine, making them ideal for builders who want a clean, simple fuel system layout.

3. What are the advantages of a non-return LS fuel system?

A non-return fuel system offers several benefits:

• Simpler plumbing layout
• Fewer fuel lines to route
• Cleaner engine compartment
• Easier installation
• Reduced fittings and connections
• Excellent reliability for off-road vehicles

These advantages make returnless systems extremely popular in rock crawlers, rock bouncers, dune buggies, Sand Rails, trail rigs, and custom LS swap projects.

4. Is this kit suitable for off-road use?

Yes. This fuel system was assembled specifically for demanding off-road environments. The Fragola -6 AN hose and fittings, Walbro fuel pump, and integrated fuel pressure regulator provide a durable solution capable of handling the vibration, impacts, and harsh conditions commonly found in rock crawling, trail riding, Ultra4 racing, mud trucks, and custom off-road vehicles.

5. Can this fuel system support a modified LS engine?

This kit is ideal for stock and moderately modified naturally aspirated LS engines. Higher horsepower combinations may require larger fuel pumps, upgraded injectors, larger fuel lines, or additional fuel system modifications. Contact us if you're building a high-horsepower LS engine and need assistance selecting the correct fuel system.