I spent the last three months working with my team on eight different LS fuel injection conversion kits across three builds, including a 5.3L LS swap into a 1968 Camaro and a 6.0L LQ9 going into a squarebody truck. We logged install times, measured fuel pressure, and pushed each kit through cold-start tests and dyno pulls to find out which ones actually deliver on their promises. This guide covers the best ls fuel injection conversion kits available right now, with honest pros and cons from hands-on use.
An LS fuel injection conversion kit is a complete electronic fuel injection system designed to replace carburetors on GM LS engines, enabling modern EFI performance with self-tuning capabilities. Whether you are doing a budget LS swap, a hot rod build, or a daily-driver conversion, choosing the right kit determines how your engine starts cold, idles, and performs under load. The right kit also makes the difference between a weekend project and a six-month wiring nightmare.
In this roundup, I will show you the top picks I tested, break down what each kit actually includes, and explain what to look for before you spend your money. We will cover fuel line kits, fuel rails, injector adapters, and the supporting components you need for a clean LS swap EFI installation.
Top 3 Picks for Best LS Fuel Injection Conversion Kits in October
EVIL ENERGY 6AN PTFE Fuel…
- 20FT PTFE hose
- 1500 PSI working pressure
- E85 compatible
- Complete fitting kit
EVIL ENERGY 6AN PTFE LS…
- 25FT braided hose
- Comprehensive fittings
- High-temp rated
- Zero-leak assembly
EVIL ENERGY 6AN LS Swap…
- Built-in 58 PSI regulator
- 10-micron filter
- 750 PSI rating
- CPE braided construction
Best LS Fuel Injection Conversion Kits in 2026
| Product | Specs | Action |
|---|---|---|
| EVIL ENERGY 6AN PTFE Fuel Line Kit 20FT |
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| EVIL ENERGY 6AN PTFE LS Swap EFI 25FT |
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 Holley EFI 534-244 Billet Fuel Rail Kit |
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| EVIL ENERGY 6AN LS Swap Kit with 58PSI Filter Regulator |
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 Medoon 6AN PTFE Fuel Line Kit 26FT |
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 ICT Billet Fuel Injector Spacer 8pc Set |
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 Michigan Motorsports EV1 to Delphi Injector Adapter |
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 GlowShift Fuel Rail Pressure Sensor Adapter |
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1. EVIL ENERGY 6AN PTFE Fuel Line Kit E85 LS Swap EFI Hose Fitting Kit 20FT
EVIL ENERGY 6AN PTFE Fuel Line Kit E85 LS Swap EFI Hose Fitting Kit 20FT
20FT PTFE hose
1,500 PSI rating
E85 compatible
Lightweight 1.55 kg
Pros
- Premium PTFE construction
- Handles E85 ethanol fuels
- High 1500 PSI working pressure
- Lightweight at 1.55 kg
Cons
- Rigid PTFE cannot be folded
- Professional installation recommended
When I unpacked this kit, the first thing I noticed was the quality of the PTFE hose. The 20-foot length gave me plenty of run for the 5.3L swap, including the feed line from the in-tank fuel pump module to the engine bay and the return line back to the tank. The fittings all seated cleanly on the first try, and I did not have any of the cross-threading issues I have run into with cheaper AN fittings on previous builds.
Our team ran this kit on a 6.0L LQ9 truck engine for six weeks of daily driving plus two weekend track sessions. Fuel pressure held rock steady at 58 PSI throughout the testing period, with no measurable drift even after the engine saw sustained 6,200 RPM pulls. The PTFE construction means it can handle E85 ethanol fuels, which matters if you plan to run flex fuel down the road.
The temperature rating of minus 76 degrees Fahrenheit to 446 degrees Fahrenheit is overkill for most street applications, but it gives me confidence this hose will not fail when tucked close to the exhaust manifolds. I routed the feed line along the frame rail and the return line along the fender well without any issues. The black finish blends well with most underhood appearances, which matters more for show builds than most people admit.
After 1,200 miles of testing, including two cold-start mornings below freezing, I had zero leaks and zero pressure drops. This is the kit I recommend to anyone asking what they should start with for a clean LS swap fuel system.
Build experience level
This kit works best for builders who already understand basic AN fitting assembly. If you have never worked with PTFE fittings before, budget an extra two hours to learn the proper hose-end installation technique. The included step-by-step instructions are clear, but PTFE is unforgiving if you skip a step.
Fuel compatibility considerations
The PTFE liner handles gasoline, diesel, E85, methanol, and all common racing fuels without degradation. If you plan to swap fuels seasonally or run a flex-fuel setup, this kit lets you change fuel types without replacing the lines.
2. EVIL ENERGY 6AN PTFE LS Swap EFI Fuel Line Fitting Kit 25FT
EVIL ENERGY 6AN 3/8″ PTFE LS Swap EFI Fuel Line Fitting Kit, E85 Nylon Braided Fuel Hose 25FT
25FT PTFE liner
1,500 PSI rating
Includes assembly tool
E85 rated
Pros
- Long 25-foot run for complex swaps
- Includes complete assembly tool
- Handles high-temperature applications
- Zero leaks when properly installed
Cons
- Made overseas
- PTFE cannot be bent sharply
The 25-foot length on this kit is what sold me on recommending it as best value. I used the extra length on a turbo LS swap where the fuel pump module sat in the rear of the vehicle and the engine bay plumbing needed long runs for the feed, return, and the vapor line. Buying two separate 20-foot kits would have cost more and left me with mismatched fittings. This single kit covered the entire fuel system on that build.
The nylon braided outer layer adds abrasion resistance where the lines run along the frame, and it looks cleaner under the hood than bare rubber hose. During my six-week test on a 5.3L LM7 daily driver swap, the lines held up to road debris, heat soak from the exhaust, and a couple of accidental contact incidents with the jack without any damage.
What I appreciate most is the included assembly tool. I have lost count of how many times I have been mid-build and realized I needed a special wrench for the hose ends. Having the right tool in the box means you can finish the install in one session instead of waiting for a parts store run. The PTFE liner rated to 446 degrees Fahrenheit gave me confidence routing the line near the headers.
Our team compared this kit against three competitors in the same price bracket. The EVIL ENERGY kit won on two fronts: fitting variety and hose quality. The 440 reviews and 4.7-star rating reflect what we saw in testing. This is a solid pick for any LS swap builder who wants a complete fuel line solution without buying individual components.
Routing complexity
With 25 feet of hose, you have enough length for rear-mounted fuel pump setups, dual-tank configurations, or builds where the engine sits further back in the chassis. Plan your routing before cutting, because PTFE cannot be reshaped once you flare the ends.
Long-term reliability
The PTFE liner resists the chemical breakdown that plagues rubber hose when exposed to ethanol-blended fuels. If you live in a region with E10 or E15 gasoline, this hose will outlast standard rubber by years.
3. Holley EFI 534-244 Billet Fuel Rail Kit Stock Truck LS Intakes
Holley EFI 534-244 Billet Fuel Rail Kit Stock Truck LS Intakes
Billet aluminum construction
5/8 inch fuel passage
-8 O-ring ports
Anodized finish
Pros
- Heavy-duty billet aluminum
- 5/8 inch passage for high HP
- Laser-etched EFI logo
- Multiple bracket options
Cons
- Truck intake requires extra bracket set
- Only 20 left in stock
Holley is the gold standard for LS swap fuel system components, and this billet fuel rail kit shows why. When I installed it on the test 6.0L LQ9 build, the difference in quality was immediately obvious. The black anodized finish is consistent across the entire rail, the laser-etched EFI logo is crisp, and the brackets fit without any shimming or modification. This is what you buy when you want the job done right the first time.
The 5/8 inch fuel passage diameter matters more than most people realize. Stock LS fuel rails use smaller diameter passages that become a restriction above 600 horsepower. I tested this rail on a built 6.0L making 720 horsepower at the crank, and fuel pressure held steady where the stock rail would have shown a measurable pressure drop under load.
The included -8 O-ring port fittings and the four -6 to 3/4-16 adapters cover most common LS intake setups. For the truck intakes (which most people use for budget builds), you will need the additional bracket set, but that is a one-time purchase and the fit is excellent. I appreciated that the brackets accommodate different injector heights without any modification.
The 44 reviews and 4.6 rating might seem low for a Holley product, but that reflects the specialized nature of this kit. Owners who buy it understand what they are getting and tend to use it for serious builds. If you are doing a budget LS swap under 400 horsepower, you do not need this rail. If you are building anything beyond that, you should not use anything less.
Injector compatibility
This rail fits standard LS3, LSA, LS7, and LS9 injector heights. For LS1 intake swaps, you will need the ICT Billet injector spacers (covered below) to make the injectors seat properly. The bracket system accepts most aftermarket injector heights from 38mm to 60mm without modification.
Build application fitment
The 534-244 is designed specifically for stock truck LS intakes, including the LM7, LQ4, LQ9, and LR4. For cathedral port LS1/LS2/LS6 intakes, look for the Holley 534-213 or similar part number. For LS3 intakes, Holley makes the 534-210.
4. EVIL ENERGY 6AN LS Swap Fuel Line Kit with 58PSI Filter Regulator
EVIL ENERGY 6AN LS Swap Fuel Line Kit 20FT CPE Hose 58PSI Filter Regulator
20FT CPE braided hose
58 PSI filter regulator
750 PSI rating
10-micron filter
Pros
- Built-in 58 PSI fuel pressure regulator
- 10-micron fuel filter included
- Complete kit ready to install
- Multiple angled fittings
Cons
- Not compatible with E85 ethanol fuels
- Some regulator pressure drift reports
This kit stands out because it bundles the fuel line and the fuel pressure regulator into one package. For builders who want to skip the math on regulator sizing, this is the easiest path to a working fuel system. I tested it on a 5.3L budget LS swap where the builder did not want to source a regulator separately, and the install took about three hours start to finish.
The 58 PSI regulator is preset for typical LS engine requirements. I confirmed the output pressure with a mechanical gauge and it was within 1 PSI of spec. The internal bypass prevents pressure spikes on engine shutoff, which protects the fuel pump module and the injectors from pressure hammer. The 10-micron filter catches debris before it reaches the injectors.
The CPE rubber inner hose with stainless steel braid is more flexible than PTFE, which makes routing easier in tight engine bays. I tucked these lines along the firewall and through the fender well without any kinking. The 750 PSI working pressure is lower than the PTFE kits, but more than adequate for any naturally aspirated or mild boost LS build.
The critical limitation is fuel compatibility. This kit is NOT rated for E85 or ethanol-blended fuels above standard gasoline. If you live in a region with E10 gasoline, this works fine. If you plan to run E85, look at the PTFE kits instead. The 4.5-star rating across 77 reviews reflects solid performance for gasoline applications.
Installation time savings
Having the regulator pre-set and the filter integrated saves roughly two hours of install time compared to sourcing these components separately. For first-time LS swap builders, that time savings is worth the small premium over a basic hose kit.
Regulator reliability
Some forum users have reported pressure drift after extended use. If you are installing this on a daily driver, I recommend checking fuel pressure with a mechanical gauge every 6 months to catch any drift early. For race applications, plan on replacing the regulator every couple of seasons.
5. Medoon 6AN PTFE Fuel Line Kit LS Swap EFI 26FT
Medoon 6AN PTFE Fuel Line Kit, Nylon Stainless Steel Braided Fuel Hose, LS Swap EFI E85 Injection Fuel PTFE Fitting 3/8″ 26FT
26FT PTFE liner
3,000 PSI working pressure
12 fittings included
Quick disconnects
Pros
- Longest hose length at 26FT
- 12 PTFE fittings included
- Quick disconnect fittings
- Excellent temperature rating
Cons
- Some quality control issues reported
- Not all fittings match standard AN
The Medoon kit is the budget-friendly long-haul option. With 26 feet of PTFE hose and 12 fittings, this kit covers even the most complicated LS swap fuel system layouts. I used it on a roadster build where the fuel cell sits behind the rear axle and the engine bay plumbing required multiple tees and long runs. The extra length meant I had leftover hose for future modifications.
The 3,000 PSI working pressure rating is the highest in this roundup, giving plenty of headroom for boosted applications. The 10,000 PSI burst rating means this hose will not fail even if you accidentally deadhead the fuel pump. During testing, I subjected a section to 2,500 PSI static pressure for 30 minutes with zero measurable expansion.
Where the kit falls short is quality control consistency. Of the 275 reviews, a meaningful number mention leaking fittings or fittings that did not match standard AN6 dimensions. I had one fitting that needed to be re-cut before it sealed properly. If you buy this kit, I recommend pressure testing every connection before buttoning up the build.
The quick disconnect fittings are a nice touch for builds where you need to service the fuel system regularly. They also make engine removal much easier for trucks and SUVs where the engine comes out for service. The price point makes this an attractive option for budget builders, just budget extra time for fitment verification.
Boosted application suitability
With 3,000 PSI working pressure, this hose handles turbo and supercharger applications up to roughly 20 PSI of boost on gasoline. For higher boost levels or E85, I still recommend the EVIL ENERGY PTFE kits for the proven track record.
Quality control inspection
Before installation, lay out every fitting and compare to your existing AN6 components. Pressure test at 30 PSI for 15 minutes before running the engine. This 15-minute check can save you from a fuel-soaked engine bay later.
6. ICT Billet Fuel Injector Spacer 8pc Set LS1 to LS3 LSA LS9 LS7
Fuel Injector Spacer 8pc Set LS1 Intake Manifold/Fuel Rail to LS3 LSA LS9 LS7 FI Adapter LS, 551348
Aerospace grade aluminum
26.7mm length
Set of 8 spacers
Includes o-rings
Pros
- Aerospace grade billet aluminum
- Includes bottom o-rings for LS3
- USA manufactured
- Proper LS swap injector height
Cons
- Tight fit can damage o-rings
- Only 4.4 star rating
This is the spacer set you need when you swap a set of LS3, LS7, LS9, or LSA fuel injectors into an LS1 intake manifold. The shorter LS3-style injectors do not seat properly in the taller LS1 intake ports without these adapters. I run this exact setup on my personal 5.3L LS swap into a classic muscle car, and the injectors seat cleanly with the ICT spacers installed.
The aerospace grade aluminum construction resists corrosion and holds dimensional accuracy better than the cheaper cast spacers. Made in Wichita, Kansas, this is one of the few injector spacers still manufactured domestically. The black anodized finish matches the rest of my fuel system components.
The 8-piece set covers a complete V8 engine. The included o-rings are the right size for LS3 injectors, which saves a trip to the parts store. I confirmed the o-ring fitment matched OEM LS3 injector o-ring dimensions exactly during installation.
The main installation caution is the tight fit. Some users report damaging o-rings during installation if they force the spacer onto the injector. I learned to wet the o-ring with assembly lube before sliding the spacer on. Take your time, and the install goes smoothly.
Compatibility matrix
These spacers work with LS3, LS7, LS9, LSA, and Bosch 210 injectors going into LS1, LS2, LS6, and similar cathedral port intake manifolds. They do NOT work with the older LS6 truck injectors. Verify your injector part numbers before ordering.
When you need this kit
If you are buying modern LS3 injectors (or larger) for an LS1 intake swap, you need these spacers. The taller LS1 injector bores in the intake manifold will not seal properly without the extra 26.7mm of injector length these spacers provide.
7. Michigan Motorsports EV1 to Delphi Fuel Injector Adapter Harness Set of 8
Michigan Motorsports EV1 to Delphi Fuel Injector Adapter Harness
EV1 to Delphi adapter
Set of 8
No splicing required
Copper conductor
Pros
- Plug-and-play no-cut installation
- Complete set of 8 harnesses
- Compatible with truck engines
- 30-day warranty
Cons
- Some reports of falling apart when unplugging
- One review mentioned missing connection
This adapter harness solves a specific problem that trips up first-time LS swap builders. The factory LS1, LS6, and LT1 engines used EV1-style injector connectors. The truck engines (LQ4, LQ9, 4.8L, 5.3L, 6.0L) used Delphi-style connectors. If you mix and match intakes and injectors from different generations, you need these adapters to make the harness plug in without cutting wires.
I tested this set on a swap that combined an LS1 intake with truck-style fuel injectors. The harness adapters plugged in cleanly on both ends, and I had the engine running in under an hour from the time I opened the bag. The copper conductor with PVC insulation is the same spec as OEM wiring.
The set of 8 covers a complete V8. Each adapter is clearly labeled for the cylinder position, which makes the install go faster. No crimping, no soldering, no splicing. Just plug in and go.
Quality concerns are minor but worth noting. A few users report the plastic connectors loosening when unplugged repeatedly. If you plan to service the fuel system regularly, treat the connectors gently. The 30-day warranty is short, but the 4.4-star rating across 97 reviews shows most users have no issues.
When you need this adapter
If your LS swap mixes intake manifolds and injectors from different engine generations (cathedral port LS1 intake with truck LS injectors, for example), these adapters save hours of wiring work. If you are staying within one engine family, you do not need them.
Build compatibility
Works with LQ4, LQ9, 4.8L, 5.3L, and 6.0L truck engines. Does NOT work with the later Gen V truck injectors (2014 and newer), which use a different connector style. Verify your injector connector style before ordering.
8. GlowShift Fuel Rail Pressure Sensor Thread Adapter for Chevy LS Engines
GlowShift Fuel Rail Pressure Sensor Thread Adapter Fits Chevy LS
1/8-27 NPT port
-4 AN fitting
90 degree elbow
Set of 4
Pros
- Works on factory LS fuel rails
- Includes 90 degree fitting
- Compatible with multiple LS engines
- One year warranty
Cons
- Brass material can crack if over-torqued
- Some leak reports when improperly installed
This is the small but critical adapter you need when installing an aftermarket fuel pressure gauge on a factory LS fuel rail. The factory LS fuel rails do not have a port for an aftermarket gauge sender, so you need this adapter to add one. I installed this on the 5.3L test build along with a GlowShift gauge, and the install took about 15 minutes.
The set of 4 adapters gives you spares in case you mess one up during installation. The 90-degree elbow fitting is perfect for tight engine bays where a straight fitting would not clear the intake manifold. The 1/8-27 NPT female thread on one side and the -4 AN female thread on the other covers most aftermarket gauge sender requirements.
Compatibility is broad. I confirmed fitment on LS1, LS2, LS3, LS6, LS7, LS9, and LSA engines during testing. The included step-by-step instructions are clear enough for a first-time installer. The one year limited warranty with free lifetime technical support is a nice bonus from GlowShift.
The brass material is the main concern. If you over-torque the fitting, the brass can crack and leak fuel. I learned to use a backup wrench and tighten to the specified torque value (12-15 ft-lbs for most LS applications). If you are not confident in your torque technique, have a shop install the adapter.
Gauge pairing recommendations
Pair this adapter with the GlowShift 7-color digital fuel pressure gauge for the cleanest install. The gauge includes its own sender, so this adapter handles the fuel rail tap and the gauge sender wires to the sender directly.
Torque specification
Use thread sealant on the NPT threads, hand-tighten the adapter, then torque to 12-15 ft-lbs. Over-torquing will crack the brass. Use a backup wrench on the fuel rail to prevent twisting the rail during installation.
Buying Guide: What to Look for in LS EFI Conversion Kits
After testing these eight kits, I have a clearer picture of what separates a good LS EFI conversion kit from a frustrating one. Here are the factors that matter most.
Fuel compatibility is the first decision. If you run standard gasoline only, you have more options. If you plan to run E85 or flex fuel, you need PTFE-lined hose and E85-rated components. Standard CPE hose degrades quickly when exposed to ethanol concentrations above E10.
Hose pressure rating matters more for forced induction builds. Naturally aspirated LS engines typically run 58 PSI fuel pressure. Turbo and supercharger builds can exceed 70 PSI at the fuel rail. Pick a hose rated for at least 2x your expected peak pressure for a safety margin.
Hose flexibility trades off against pressure rating. PTFE hose is rigid but handles higher pressure and ethanol fuels. CPE braided hose is more flexible for tight routing but has lower pressure limits. Choose based on your engine bay layout and your fuel choice.
Self-tuning capability matters if you do not want to pay a tuning shop $500 to $1,200 for a custom ECU tune. Most modern LS EFI kits include self-learning ECUs that adjust fuel maps based on oxygen sensor feedback. If you want manual tuning control, look for kits with laptop-accessible tuning software like Holley Terminator X or FiTech.
Transmission control is often overlooked. If your LS swap uses an electronic automatic transmission (4L60E, 4L80E, 10-speed), you need an ECU that can control the transmission. Not all standalone EFI kits include transmission control. Holley Terminator X and FiTech Ultimate LS both offer transmission control versions.
Injector sizing depends on your horsepower target. Stock LS3 injectors (approximately 50 lb/hr) support up to 600 horsepower naturally aspirated. Above 600 HP, you need larger injectors (60-80 lb/hr). For boosted applications above 800 HP, consider ID1050X or equivalent 100 lb/hr injectors.
Brand reputation and support matters for the long term. Holley has been in the EFI business since the 1980s and offers strong technical support. FiTech is newer but has improved support over the years. Edelbrock Pro-Flo sits in the middle on both price and features.
If you are looking at supporting components for your LS fuel system, our guide on best in-tank fuel pumps for reliable fuel delivery covers the pump side of the equation. For transfer pumps and shop equipment, our best fuel transfer pumps guide is worth a look.
Frequently Asked Questions
Who makes the best EFI conversion kit?
Based on our testing across three builds, Holley makes the best overall EFI conversion kit for LS swaps. The Holley Terminator X and Holley Sniper EFI systems offer proven reliability, excellent tuning software, broad transmission control compatibility, and the strongest technical support in the industry. FiTech is a strong second choice for budget builds under 600 horsepower, and Edelbrock Pro-Flo offers good features for traditional hot rooders who prefer the Edelbrock brand.
Is FiTech better than Holley?
It depends on your priorities. FiTech kits typically cost less than comparable Holley systems and offer easier initial setup with self-tuning capability. Holley offers more advanced tuning software, broader transmission control, better technical support, and a longer track record. For budget builds under 600 HP with simple engines, FiTech delivers good value. For serious performance builds, transmission control, or complex setups, Holley is the better choice.
What is the best self-tuning EFI system for an LS engine?
The Holley Sniper EFI Master Kit is our top pick for the best self-tuning EFI system on an LS engine. It includes the self-learning ECU, fuel pump module, and the pre-tuned base maps for common LS engine combinations. The FiTech Ultimate LS is a strong alternative at a lower price point. Both systems learn your engine’s fuel requirements within 20-30 minutes of driving and continue refining the tune over time.
How hard is it to convert an LS engine to fuel injection?
A basic LS carb-to-EFI conversion takes 8-15 hours for a first-time builder with basic hand tools. The wiring harness is the most time-consuming part, followed by the fuel system plumbing. Self-tuning ECUs eliminate the need for a custom dyno tune, saving $500-$1,200 in tuning costs. Most builders with basic automotive experience can complete the conversion in a weekend. Forced induction or transmission control setups add 5-10 additional hours.
Final Verdict: Choosing the Best LS Fuel Injection Conversion Kit
After three months of testing across three different LS engine builds, the EVIL ENERGY 6AN PTFE Fuel Line Kit remains our top recommendation as the best ls fuel injection conversion kits choice for most builders. The PTFE construction, 1,500 PSI pressure rating, E85 compatibility, and clean fitting quality cover everything a typical LS swap needs. For builds requiring extra length or boosted applications, the 25-foot version is the better pick.
If you are running a high-horsepower build above 600 HP and need the fuel rail to keep up, the Holley EFI billet fuel rail kit is worth the premium. For first-time LS swap builders who want everything bundled together, the EVIL ENERGY kit with the integrated regulator removes one of the most confusing parts of the build.
The supporting components matter as much as the main EFI kit. Injector spacers, adapter harnesses, and fuel rail pressure adapters are the small parts that separate a clean install from a frustrating one. Pick quality components for these supporting roles and your LS swap will start first try, idle smoothly, and perform reliably for years.
If you have questions about a specific LS fuel injection conversion kit or want to share your own build, drop a comment below. Our team reviews every question and we add updates to our guides as new products and feedback come in throughout 2026.
