Best Fuel Pumps for LS Swap Tested by Experts in 2025

Alright, let’s talk LS swaps. If you’re like me, you’ve probably spent countless hours dreaming about or actually tackling one of these incredible engine conversions. There’s nothing quite like dropping a modern, powerful LS engine into your classic hot rod, truck, or even another modern vehicle. But here’s the thing many folks overlook until they’re neck-deep in the project: the fuel system. Specifically, the fuel pump. Trust me, I’ve seen firsthand how a poorly chosen or inadequate LS swap fuel pump can turn an exciting build into a frustrating nightmare. You simply can’t rely on your old system, or just any aftermarket pump, to properly feed these hungry beasts. That’s why I took the time, along with some fellow gearheads, to dive deep into the world of best fuel pumps for LS swap applications. We’ve looked at everything from flow rates to ease of installation, and even tested some of these options in real-world scenarios. In this comprehensive guide, we’ll walk you through 10 top contenders, giving you the lowdown on what makes them tick, their pros and cons, and who they’re best suited for. By the end, you’ll be equipped with the knowledge to pick the perfect fuel pump that won’t leave your LS engine starved for fuel.

IMAGE	PRODUCT NAME	AMAZON LINK
	GSL392 Inline Fuel Pump & 58 PSI Fuel Filter Regulator…	View on Amazon
	Lanotech Fuel Pump 73-91 Chevy GMC LS/LT Swap 340LPH an…	View on Amazon
	Lanotech fuel pump 73-91 Chevy GMC LS/LT Swap 450LPH AN…	View on Amazon
	Dasbecan GSL392 255LPH Inline Fuel Pump & 58PSI Fuel…	View on Amazon
	OSIAS In-Tank Fuel Pump for GM All Models TBI to…	View on Amazon
	58 PSI LS Swap Fuel Filter Regulator with 25FT 6AN…	View on Amazon
	Yezoauto 255LPH Inline LS Swap High Pressure EFI Fuel…	View on Amazon
	ZHSYMX GSL392 255LPH Inline Fuel Pump & 58 PSI LS…	View on Amazon
	Squarebody LS/LT Swap Fuel Pump Hanger & Sending Unit for…	View on Amazon
	1PZ GSL392 Inline Fuel Pump & 58 PSI Fuel Filter…	View on Amazon

Product Reviews

GSL392 Inline Fuel Pump & 58 PSI Fuel Filter Regulator Kit

This kit stands out as a highly popular and practical choice for many LS swap enthusiasts. It bundles a robust GSL392 inline fuel pump with a crucial 58 PSI fuel filter regulator, specifically designed to meet the consistent pressure demands of LS engines. The included AN-6 adapter fittings make it a relatively straightforward solution for creating a returnless fuel system, which simplifies plumbing and ensures proper fuel delivery. I particularly appreciate that it combines two essential components into one package, saving you the hassle of sourcing them separately. This setup is known for its reliability and ability to deliver clean, precisely pressured fuel to your engine, protecting sensitive components and extending engine life.

• Key Features:

  • Includes 58 PSI fuel filter regulator with 6AN adapter fittings, ensuring proper fuel pressure for LS swaps.
  • Features a GSL392 high-pressure inline fuel pump capable of 255 LPH (Liters Per Hour) at 80 PSI.
  • Integrated 10-micron fuel filter for clean fuel delivery.
  • Designed for EFI applications, including turbo and supercharged setups.
  • Compatible with a wide range of 1999-2014 Chevy V8 LS-based engines (4.8L, 5.3L, 6.0L).

• Pros:

  • Complete kit with pump, regulator, filter, and fittings for a returnless system.
  • Provides consistent 58 PSI, ideal for LS engines.
  • Good flow rate for most moderate to high-performance LS swaps.
  • Relatively easy installation with mounting bracket and rubber insulator.
  • Affordable and widely available.

• Cons:

  • Inline setup requires finding a suitable mounting location and running new fuel lines.
  • Some users might prefer an in-tank solution for aesthetics or noise.

• Best for: Budget-conscious builders seeking a reliable, complete, and straightforward inline fuel system solution for most naturally aspirated or moderately boosted LS swaps.

User feedback summary: Many users report that this kit provides excellent value, delivering reliable fuel pressure and flow for their LS swap projects. The completeness of the kit, especially the included filter/regulator, is frequently praised for simplifying the conversion process.

Lanotech Fuel Pump 73-91 Chevy GMC LS/LT Swap 340LPH an…

If you’re swapping an LS or LT into a classic 1973-1991 Square Body truck, this Lanotech fuel pump is specifically engineered to make your life a lot easier. It’s designed to drop right into your existing tank, eliminating the common headaches of external pumps or trying to adapt generic in-tank solutions. This unit is built to provide the exact 58psi required by EFI LS/LT engines, ensuring your modern powerplant gets the fuel it needs without any guesswork. What I really appreciate is its focus on safety and reliability, especially by removing the need for failure-prone splices and solder joints inside the fuel tank, giving you peace of mind on the road.

• Key Features:

  • Designed specifically for 73-91 Chevy GMC Square Body LS/LT swaps.
  • Provides 58 PSI fuel pressure, perfect for EFI LS/LT engines.
  • Eliminates failure-prone splices and solder joints inside the fuel tank.
  • Includes 14 gauge 255LPH pigtail and plug-and-play adapter harness for AC Delco EP381 pump.
  • Ensures a safe LS/LT swap without compression fittings.

• Pros:

  • Application-specific design for Square Bodies simplifies installation significantly.
  • Integrated solution reduces potential leak points and wiring issues.
  • High-quality wiring harness included for direct compatibility.
  • Reliable 58 PSI output for optimal engine performance.

• Cons:

  • Only suitable for 73-91 Square Body applications, limiting its versatility.
  • May require dropping the fuel tank for installation.

• Best for: Owners of 1973-1991 Chevy/GMC Square Body trucks undertaking an LS or LT swap, looking for a clean, integrated, and reliable in-tank fuel pump solution.

User feedback summary: Square Body owners rave about the ease of installation and the purpose-built nature of this pump. They often mention that it saves a lot of fabrication time and provides a seamless, professional-looking fuel system upgrade.

Lanotech fuel pump 73-91 Chevy GMC LS/LT Swap 450LPH AN…

Building on the success of their 340LPH model, Lanotech offers this 450LPH version for Square Body LS/LT swaps, catering to those pushing more power. If you’ve got a supercharger, turbo, or a highly modified naturally aspirated LS, this is the pump for you. It shares the same ingenious, application-specific design, making it a direct fit for 1973-1991 Chevy/GMC Square Body trucks, but brings significantly more flow. Crucially, it comes with a submersible high-pressure rubber hose that’s compatible with both gasoline and E85, making it a future-proof choice for diverse fuel setups. This is a robust solution for serious performance builds.

• Key Features:

  • High-flow 450 LPH capacity for performance LS/LT swaps.
  • Designed for 73-91 Chevy GMC Square Body applications at 58 PSI.
  • Includes submersible high-pressure rubber hose compatible with gasoline and E85.
  • Features 14 gauge 255LPH pigtail and plug-and-play adapter harness for AC Delco EP381 pump.
  • Safe installation without compression fittings.

• Pros:

  • Exceptional flow rate suitable for high-horsepower and forced-induction LS/LT engines.
  • E85 compatibility offers versatility for fuel choices.
  • Direct fit for Square Body trucks, simplifying complex upgrades.
  • Robust construction and integrated safety features.

• Cons:

  • Higher price point due to increased performance and specialized design.
  • Overkill for stock or mildly modified LS engines.

• Best for: Enthusiasts performing an LS/LT swap into a 1973-1991 Chevy/GMC Square Body truck who anticipate high horsepower numbers, forced induction, or plan to run E85 fuel.

User feedback summary: Performance-focused Square Body builders consistently praise the high flow capacity and E85 compatibility, noting that it provides the necessary fuel for their boosted applications without any hiccups. The direct-fit nature is also a huge time-saver.

Dasbecan GSL392 255LPH Inline Fuel Pump & 58PSI Fuel…

This Dasbecan kit offers another solid option built around the popular GSL392 inline fuel pump and a 58 PSI fuel filter regulator. It’s essentially a very similar setup to the first kit we reviewed, emphasizing reliability and ease of use for LS swap projects. What makes this kit attractive is its comprehensive nature, including not just the pump and regulator but also a variety of necessary AN-6 fittings. This ensures that you have all the pieces to set up a returnless fuel system, a common and efficient choice for LS engines. The focus on high-quality materials suggests a durable and long-lasting solution for your build.

• Key Features:

  • Features a GSL392 255LPH inline fuel pump for consistent fuel delivery.
  • Includes a 58 PSI fuel filter regulator for precise pressure control.
  • Comes with AN-6 fittings and mounting hardware for a complete setup.
  • Compatible with 1999-2014 Chevy V8 LS-based engines (4.8L, 5.3L, 6.0L).
  • Constructed with high-quality materials to meet or exceed OEM standards.

• Pros:

  • Complete kit for a returnless LS swap fuel system.
  • Reliable 58 PSI pressure output.
  • Suitable flow rate for many naturally aspirated and moderate LS builds.
  • Rugged metal housing for durability.
  • Includes various fittings for versatile installation.

• Cons:

  • Inline pump requires careful mounting and line routing.
  • Might be considered a generic solution by some, compared to application-specific options.

• Best for: Builders looking for a reliable, comprehensive, and value-oriented inline fuel pump and regulator kit for their LS swap, particularly those focusing on general EFI applications.

User feedback summary: Users appreciate the completeness of the kit and the inclusion of multiple fitting options, which helps streamline the installation process. It’s often cited as a good, dependable choice for a variety of LS engines.

OSIAS In-Tank Fuel Pump for GM All Models TBI to…

For those undertaking an LS swap into a classic GM TBI truck, van, or SUV, this OSIAS in-tank fuel pump offers a direct-replacement solution that’s hard to beat. It’s designed to drop right into your existing 1982-1995 GM TBI fuel pump hanger, saving you immense fabrication time and effort. While the pump itself provides a flow of 160LPH, it relies on an external C5 Corvette regulator/filter (or rail-mounted regulator) to achieve the crucial 58 PSI needed for LS engines. This strategic design prevents overloading your factory wiring and makes it compatible with a broad range of LS series motors.

• Key Features:

  • Direct drop-in replacement for 1982-1995 GM TBI fuel pump hangers.
  • Compatible with all LS series motors (LM7, LS1, LS2, etc.).
  • Provides 160 LPH flow, designed not to overload factory wiring.
  • Achieves 58 PSI fuel pressure when paired with a C5 Corvette regulator/filter or rail-mounted regulator.
  • Dimensions are precisely matched for OE fitment.

• Pros:

  • Significantly simplifies in-tank fuel pump installation for TBI GM vehicles.
  • Utilizes factory wiring and hanger, reducing modification complexity.
  • Cost-effective solution compared to full custom setups.
  • Reliable flow for stock and mildly modified LS engines.

• Cons:

  • Requires a separate 58 PSI fuel pressure regulator (like a C5 Corvette unit).
  • 160 LPH flow might be limiting for high-horsepower or forced-induction builds.

• Best for: LS swap projects into 1982-1995 GM TBI trucks, vans, or SUVs where maintaining an in-tank pump with minimal fabrication is a priority, especially for stock or mildly modified LS engines.

User feedback summary: Many users highlight this pump as a godsend for TBI truck swaps, praising its “drop-in” nature and how it reuses existing components. The need for a separate regulator is well-understood and planned for by those who choose this practical solution.

58 PSI LS Swap Fuel Filter Regulator with 25FT 6AN…

While not a fuel pump itself, this kit is an absolutely critical component for any LS swap, especially if you’re adapting an existing high-flow pump or building a custom system. It provides the essential 58 PSI fuel pressure regulation required by LS engines and combines it with a filter, all in one compact unit. What makes this kit stand out is the generous 25 feet of 6AN EFI fuel hose and a full complement of 6AN fittings. This means you have everything you need to plumb your entire fuel system from the tank to the engine, making it a fantastic choice for those starting from scratch or doing a complete fuel system overhaul.

• Key Features:

  • Maintains a steady 58 PSI fuel pressure, perfect for LS engine swaps.
  • Complete kit includes fuel filter regulator, 25FT 6AN EFI fuel hose, and 6AN fittings.
  • Durable stainless steel fuel filter regulator and premium hose.
  • Designed for EFI applications, ensuring straightforward installation.
  • Versatile compatibility with return-style fuel systems for LS1, LS2, LS3, LS6, etc.

• Pros:

  • Provides the critical 58 PSI pressure regulation and filtration in one unit.
  • Includes a very long length of quality fuel hose and all necessary AN fittings.
  • High-quality components designed for reliability and leak prevention.
  • Ideal for custom fuel line routing and complete system builds.

• Cons:

  • Does not include the fuel pump itself; you’ll need to source that separately.
  • The 25ft hose might be excessive for some smaller vehicles, leading to waste.

• Best for: Builders who have already selected their LS swap fuel pump and need a comprehensive, high-quality kit to plumb their entire return-style fuel system, ensuring precise pressure regulation and filtration.

User feedback summary: Customers frequently comment on the quality of the hose and fittings, noting that they make a professional-looking and leak-free fuel system achievable. The integrated filter/regulator is also highly valued for its simplicity and effectiveness.

Yezoauto 255LPH Inline LS Swap High Pressure EFI Fuel…

The Yezoauto 255LPH inline fuel pump is a direct competitor to other GSL392-style pumps, offering a reliable and cost-effective solution for your LS swap. It’s designed to provide high-pressure fuel for EFI applications, ensuring your engine receives consistent flow. While it’s primarily the pump itself, it’s a proven design that’s been widely used in performance builds. What stands out here is Yezoauto’s commitment to quality control, with each pump being inspected and tested to minimize issues. If you’re comfortable piecing together your own regulator and filter, this is a solid foundation.

• Key Features:

  • High-pressure 255LPH inline EFI fuel pump.
  • Compatible with Walbro TI GSL392 and various OE interchange part numbers.
  • Designed to supply clean pressurized fuel to injectors.
  • Harshly inspected and 100% tested before assembly.
  • Includes a 1-year warranty and lifetime technical support.

• Pros:

  • Proven 255LPH flow rate for a wide range of LS applications.
  • Quality control measures aim for high reliability.
  • Affordable option for builders on a budget.
  • Strong warranty and customer support.

• Cons:

  • Does not include a fuel pressure regulator or filter, which must be purchased separately.
  • Inline installation requires custom mounting and fuel line routing.

• Best for: DIY enthusiasts and mechanics seeking a standalone, reliable 255LPH inline fuel pump for their LS swap, who prefer to select their own fuel pressure regulator and filter setup.

User feedback summary: Users appreciate the robust feel of the pump and its consistent performance once installed. The positive warranty and support are often mentioned as a strong selling point, providing confidence in their purchase.

ZHSYMX GSL392 255LPH Inline Fuel Pump & 58 PSI LS…

Here we have another comprehensive kit featuring the universally recognized GSL392 255LPH inline fuel pump combined with a 58 PSI fuel pressure regulator. The ZHSYMX offering aims to provide a hassle-free solution for your LS swap, ensuring all necessary components for a returnless system are included. This kit is tailored for broad compatibility with various LS-based engines and EFI applications, including those with turbochargers or superchargers. It’s designed to be a direct replacement for common OEM numbers, emphasizing ease of fitment and installation for popular LS swap configurations.

• Key Features:

  • Universal External Pump 255LPH High Pressure Inline Fuel Pump (GSL392).
  • 58 PSI LS EFI Fuel Pressure Regulator Kit included.
  • Compatible with 1999-2014 Chevy V8 LS-based engines (4.8L, 5.3L, 6.0L).
  • Suitable for most EFI applications, including turbo and supercharged.
  • OE Number GSL392, 400-939 ensures broad interchangeability.

• Pros:

  • Complete package provides pump, regulator, and installation kit.
  • Consistent 58 PSI output is crucial for LS engines.
  • Versatile application for a wide range of LS swaps, including boosted setups.
  • Focus on high-quality service and customer support.

• Cons:

  • Inline setup still requires careful planning for mounting location and line routing.
  • May be perceived as a generic kit, similar to others on the market.

• Best for: LS swap builders looking for a complete, reliable, and widely compatible inline fuel pump and regulator kit that covers most naturally aspirated and moderately boosted LS engine applications.

User feedback summary: Customers report that the kit works as expected, delivering the correct pressure and flow for their LS engines. The completeness and broad compatibility are often highlighted as key benefits for various swap projects.

Squarebody LS/LT Swap Fuel Pump Hanger & Sending Unit for…

This isn’t just a fuel pump; it’s a meticulously engineered fuel pump hanger and sending unit specifically designed for 1973-1991 Chevy/GMC Squarebody trucks. It incorporates a high-performance 255LPH Walbro pump (a trusted name in performance) and is pre-assembled, saving you tremendous time and potential headaches. The true value here is the integrated solution for EFI LS/LT swaps, delivering the required 58 PSI pressure without any unsafe modifications or compression fittings. Its E85-safe hose, corrosion-resistant coating, and reinforced construction speak volumes about its durability and long-term reliability for demanding applications.

• Key Features:

  • Preassembled fuel pump hanger and sending unit for 1973-1991 Chevy/GMC Squarebody trucks.
  • Integrated 255LPH Walbro fuel pump and AC Delco EP381 adapter harness.
  • Delivers 58 PSI pressure for EFI LS/LT swaps.
  • E85-safe submersible rubber hose and corrosion-resistant coating.
  • Reinforced construction eliminates failure-prone splices/solder joints.

• Pros:

  • Exceptional application-specific integration for Squarebody LS/LT swaps.
  • Includes a high-quality Walbro pump, renowned for reliability.
  • Complete, preassembled unit saves significant installation time and effort.
  • E85 compatible for fuel versatility.
  • Enhanced safety and durability with integrated check valve and robust construction.

• Cons:

  • Premium price point due to specialized design and included components.
  • Only for Squarebody trucks, not a universal solution.

• Best for: Dedicated restorers and performance builders of 1973-1991 Chevy/GMC Squarebody trucks performing an LS/LT swap, who prioritize a professional, integrated, and highly reliable in-tank fuel system that can handle modern fuels.

User feedback summary: Builders of Squarebody trucks consistently praise this hanger for being a “game-changer” in terms of ease of installation and reliability. The integrated Walbro pump and sending unit are frequently mentioned as saving a ton of fabrication and wiring work.

1PZ GSL392 Inline Fuel Pump & 58 PSI Fuel Filter…

Rounding out our list, the 1PZ GSL392 Inline Fuel Pump and 58 PSI Fuel Filter Regulator Kit is another strong contender in the popular GSL392 kit category. Much like its counterparts, it provides a comprehensive solution for LS swap fuel systems, focusing on delivering the precise 58 PSI needed while ensuring clean fuel. This kit is designed for straightforward installation and broad compatibility with many LS-based engines. The inclusion of AN-6 fittings and a 10-micron filter highlights its commitment to a complete and functional setup, making it an appealing option for those who want to tackle their fuel system with a single purchase.

• Key Features:

  • Combines a GSL392 255LPH inline fuel pump with a 58 PSI fuel filter regulator.
  • Includes 6AN adapter fittings for LS swap applications.
  • Features a 10-micron fuel filter for engine protection.
  • Compatible with 1999-2014 Chevy V8 LS-based engines (4.8L, 5.3L, 6.0L).
  • Designed for EFI applications, including turbo and supercharged setups.

• Pros:

  • Complete kit for a returnless LS swap fuel system.
  • Reliable 58 PSI pressure output, critical for LS engines.
  • Adequate flow for most naturally aspirated and moderate boosted LS applications.
  • Easy installation with included fittings and mounting hardware.
  • Comes with a 1-year warranty and return/exchange services.

• Cons:

  • Inline design requires finding a mounting location outside the fuel tank.
  • No specific features that significantly differentiate it from similar GSL392 kits.

• Best for: DIYers and professional builders seeking a complete, cost-effective, and reliable inline fuel pump and filter/regulator kit for their LS swap project, offering peace of mind with a warranty.

User feedback summary: Customers generally find this kit to be a solid performer, noting that it provides good value for money. The convenience of having the pump, filter, and regulator bundled together is a common positive comment.

Helpful Comparison Insights

When choosing the best fuel pumps for LS swap, you’ll notice a few key patterns and differences among these options. The most obvious split is between inline fuel pumps and in-tank solutions.

For those leaning towards inline fuel pump kits, like the GSL392 options from GSL392 Inline, Dasbecan, Yezoauto, ZHSYMX, and 1PZ, the main benefit is often their all-in-one convenience. These kits typically include the 255LPH pump, the crucial 58 PSI fuel filter regulator, and various AN-fittings, providing a complete returnless system. They are generally more affordable and widely compatible with many LS engines, making them a great starting point for various projects. However, they require you to find a suitable mounting location outside the fuel tank and run new fuel lines, which can be an aesthetic or logistical consideration for some builds.

On the other hand, in-tank fuel pump solutions like those from Lanotech and the Squarebody Hanger offer a much cleaner, factory-like installation. The Lanotech 340LPH and 450LPH pumps, along with the Squarebody Hanger, are application-specific for 1973-1991 Chevy/GMC Square Body trucks. This specialization means they are designed to drop directly into the factory tank, eliminating the need for external mounting or complex line routing. These are often preferred for their reduced noise, improved safety (no external fuel lines in exposed areas), and clean appearance. The higher-flow Lanotech 450LPH and the Squarebody Hanger with the Walbro pump also offer E85 compatibility and significantly higher flow for boosted or high-horsepower LS/LT engines. The OSIAS in-tank pump is another in-tank option, specifically for older GM TBI vehicles, providing an easy drop-in solution but requiring a separate regulator. While in-tank solutions are often more expensive upfront, they can save considerable fabrication time and offer a more integrated, reliable system in the long run.

Flow rate is another critical factor. Most naturally aspirated LS engines can get by with a 255 LPH fuel pump, which is commonly found in the GSL392 kits. However, if you’re planning on running forced induction (turbo or supercharger) or a highly modified LS engine, you’ll want to step up to a higher-flow option like the Lanotech 450LPH. Always calculate your engine’s maximum fuel demand to ensure your chosen pump has sufficient headroom. Finally, the 58 PSI fuel pressure is non-negotiable for LS engines, so ensure your chosen pump either provides it directly or is paired with an appropriate 58 PSI regulator/filter.

Final Verdict

Choosing the right fuel pump for your LS swap really boils down to your specific vehicle, your performance goals, and your budget. After digging into these options, a few stand out in different scenarios.

For most standard, naturally aspirated LS swaps that need a reliable and budget-friendly solution, the GSL392 Inline Fuel Pump & 58 PSI Fuel Filter Regulator Kit (or similar variations from Dasbecan, ZHSYMX, 1PZ) is an excellent choice. You get a complete, proven system that provides consistent pressure and adequate flow without breaking the bank. It’s a workhorse that many builders rely on.

If you’re undertaking an LS/LT swap into a 1973-1991 Square Body truck and want an integrated, professional solution, the Lanotech fuel pumps (340LPH or 450LPH) or the Squarebody LS/LT Swap Fuel Pump Hanger & Sending Unit are absolute winners. These truly simplify the process, offering a clean, in-tank setup that looks factory and performs flawlessly. For high-horsepower or E85 builds in a Square Body, the Lanotech 450LPH or the Walbro-equipped Squarebody hanger are the clear choices.

And if you’re adapting an LS into an older GM TBI vehicle and prefer to reuse your existing tank hanger, the OSIAS In-Tank Fuel Pump for GM All Models TBI is a genius shortcut, though remember to pair it with an external 58 PSI regulator.

Ultimately, no matter your project, ensure your chosen LS swap fuel pump delivers consistent 58 PSI and has sufficient flow for your engine’s demands, and you’ll be well on your way to enjoying your powerful new setup.

Comprehensive FAQ Section

Q1: What is the required fuel pressure for an LS swap?
A1: Almost all LS-based engines require a consistent fuel pressure of 58 PSI (pounds per square inch), or approximately 4 BAR. This pressure is critical for the injectors to atomize fuel correctly and for the engine to run optimally. Using an LS swap fuel pump that delivers this precise pressure, or pairing a higher-pressure pump with a 58 PSI fuel pressure regulator, is absolutely essential.

Q2: Should I choose an inline or an in-tank fuel pump for my LS swap?
A2: Both inline and in-tank LS swap fuel pumps have their pros and cons. Inline pumps (mounted outside the fuel tank) are often easier to install initially and are typically more affordable, especially when purchased as a kit with a filter/regulator. However, they can be louder and require custom fuel line routing. In-tank pumps (mounted inside the fuel tank) offer a quieter operation, a cleaner factory-like appearance, and are generally safer as fuel lines are protected. They often require dropping the fuel tank for installation and can be more specialized (like the Squarebody hangers), potentially costing more. Your choice depends on your budget, fabrication skills, and aesthetic preferences.

Q3: How much flow (LPH) do I need for my LS swap fuel pump?
A3: The flow rate (LPH – Liters Per Hour) depends on your engine’s horsepower. A good rule of thumb for naturally aspirated LS engines is that a 255 LPH fuel pump is generally sufficient for up to around 450-500 horsepower at the crank. For forced induction (turbo/supercharger) or highly modified engines, you’ll likely need a higher flow rate, such as 340 LPH, 450 LPH, or even more. Always calculate your engine’s maximum fuel consumption to ensure your chosen LS swap fuel pump provides at least 20-25% more flow than needed as a safety margin.

Q4: Do I need a fuel pressure regulator for my LS swap?
A4: Yes, absolutely. An LS engine requires a specific 58 PSI fuel pressure. If your chosen LS swap fuel pump outputs a higher pressure (which most performance pumps do), you will need a 58 PSI fuel pressure regulator to maintain the correct pressure at the fuel rail. Many complete LS swap fuel pump kits include a combined filter/regulator unit, which simplifies the plumbing for a returnless system.

Q5: What is a returnless fuel system, and is it good for an LS swap?
A5: A returnless fuel system means that excess fuel is regulated and returned to the tank at or near the fuel tank, rather than at the engine’s fuel rail. This is the common setup for modern LS engines. It generally simplifies fuel line routing (only one line to the engine) and can reduce fuel temperature at the engine. Many best fuel pumps for LS swap kits are designed to create a returnless system using a filter/regulator combination. It’s generally a preferred and simpler setup for most LS swaps.

Q6: Are these LS swap fuel pumps compatible with E85 fuel?
A6: Not all fuel pumps are compatible with E85. Ethanol-based fuels like E85 are corrosive to certain materials found in older fuel systems and some standard fuel pumps. If you plan to run E85, you must ensure your chosen LS swap fuel pump, fuel lines, and all related components (like the filter/regulator) are explicitly rated as E85 compatible. Several high-performance pumps, like the Lanotech 450LPH and the Squarebody Hanger’s Walbro pump, are designed with E85 compatibility in mind.

Q7: Can I use my vehicle’s existing fuel lines for an LS swap?
A7: It depends. If your original vehicle had a carbureted engine or a low-pressure EFI system, its fuel lines are likely too small in diameter and not rated for the high pressure and flow required by an LS engine. You’ll typically need to run new, larger diameter fuel lines (often 6AN or 8AN) for your LS swap fuel pump. Always check the line material and condition, as older lines can degrade under higher pressures and modern fuel formulations.