Fuel Injection System Components

Shop Fuel Injection System Parts by Type

You can shop this category as complete EFI kits or as individual components for a custom build. Use the Part Type filter to jump straight to fuel injection throttle body parts or fuel injection electronic control units. Here's what you'll find:

• Self-learning throttle body EFI kits that replace a 4-barrel or 2-barrel carburetor
• Tri-Power EFI systems that replace a 3x2 carburetor setup
• LS throttle bodies in 92 mm and 102 mm sizes
• EFI fuel rails for LS1, LS6, and LS3 factory intakes
• LS standalone harness and ECU kits, including versions with transmission control

If you're comparing options across the whole system, start with our full lineup of fuel injection systems and EFI kits. The Engine Make/Size, Material, Finish, and Outlet Size filters help you narrow thousands of results to parts that match your build.

Self-Learning Throttle Body EFI Kits for Carb-to-EFI Conversions

A self-learning throttle body EFI kit lets you replace your carburetor with fuel injection without changing your 4-barrel intake. The system adjusts fueling on its own as you drive.

Holley Sniper 2 EFI conversion kits come in Black and Shiny finishes. Master kit versions add an inline pump or a Power Distribution Module. Holley also offers the Sniper Stealth 4150 self-tuning fuel injection system master kit and the Super Sniper Stealth 4150.

FiTech Fuel Injection offers the 30003 Go Street EFI 400HP System and the Go EFI 4 600 HP self-tuning system for 4-barrel intakes. You'll also find the MSD Ignition Atomic EFI Master Kit [525HP Max] and the ACES Fuel Injection Killshot 2 Pro Throttle Body EFI System. For higher-output builds, the JEGS Bandit Series EFI Throttle Body System supports up to 650HP.

Deciding between Sniper versions? Our Holley Sniper EFI buying guide compares the original Sniper with Sniper 2.

LS Throttle Bodies, EFI Fuel Rails, and Standalone ECU Kits

You can upgrade LS airflow, fuel delivery, and engine control one part at a time, or buy them together as a complete induction system.

LS throttle body options include JEGS 92 mm and 102 mm GM LS Throttle Bodies with a black anodized finish. You can also choose the Holley Sniper EFI 92mm billet LS throttle body or the FiTech 70061 Loaded LS Throttle Body 92 mm. For Gen III/IV LS engines, the FAST 54104 Big Mouth 102 mm Electronic Throttle Body is another option.

JEGS EFI fuel rails fit GM LS1 and LS6 factory intakes, with a separate version for LS3 factory intakes. Rails feed your fuel injectors, so confirm injector fitment for your intake before you order.

For LS swaps, FiTech 70050 and 70051 Ultimate LS standalone ECU and wiring harness kits run the engine without the factory computer. The 70051 adds transmission control. For a complete package, the FiTech 70001 Ultimate LS EFI Induction System covers LS1, LS2, and LS6 engines up to 500HP.

How Do You Choose the Right Fuel Injection System?

Start with three questions: how much power you make, which intake you run, and which carburetor you're replacing. Every aftermarket fuel injection system carries a horsepower rating, so pick one rated above your engine's output.

Throttle body fuel injection bolts onto a standard 4-barrel intake, which keeps a conversion straightforward. Multi-port systems, like Edelbrock Pro-Flo 4 EFI Systems, need an EFI intake manifold. Pro-Flo 4 versions fit 1986 and earlier small block Chevy, AMC 304/360/390/401 V8, and big block Chevy oval port engines.

Match your carb setup, too: the Holley Sniper EFI 2300 two-barrel 580 CFM master kit suits 2-barrel builds. The Terminator X Stealth 4150 EFI system lineup includes a 950 CFM version. The FiTech 39610 Go EFI 3x2 Tri-Power 600 HP replaces a three-carb setup.

For a deeper comparison, read our guide to fuel injection types and how they work.

Fuel System Parts You Need for an EFI Upgrade

An EFI conversion needs a fuel system that holds far more pressure than a carburetor does. Carbureted systems run about 5-7 psi, while the JEGS Bandit EFI needs 58 psi. Plan on these supporting parts:

• An electric high-pressure fuel pump sized for your power goal
• Pressure-rated fuel lines that handle EFI pressure
• A fuel pressure regulator to hold steady pressure at the rails
• Pre- and post-pump fuel filters to protect the pump and injectors
• A return-style fuel system, which many EFI conversions need

Some kits cover part of this list, such as Holley Sniper 2 master kits with an inline fuel pump. Before you order, read what you need to know about changing a carburetor to fuel injection. Then add your vehicle in the fitment selector to see the EFI parts that fit.