Put Cold-Start Troubles Behind You: Best Aftermarket EFI Systems

We love carbs, but there’s always room for fuel injection.

byHank O'Hop| UPDATED Oct 20, 2022 4:48 PM
Put Cold-Start Troubles Behind You: Best Aftermarket EFI Systems

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BYHank O'Hop/ LAST UPDATED ON October 20, 2022

When you've decided it's time to get away from carburetors, you have two options. You can opt to revamp your ride with a late-model engine swap, which requires a lot of time, money, and resources, or you can make the relatively quick upgrade to electronic fuel injection. Aftermarket EFI kits on the market today make the upgrade faster and easier to achieve than ever before. Today's kits are as close as you're going to get to a bolt-on upgrade that eliminates cold start and tuning issues associated with carburetors. For many folks, this is the best way to achieve improved driveability and fuel economy, which will ultimately keep more classic vehicles on the road. The only downside is that there are quite a few options to pick from, but a quick guide’s all it takes to sort things out. 

Best Overall
Holley Sniper EFI

Holley Sniper EFI

Holley’s Sniper EFI system is tough to beat in most situations. It’s simple, competitively priced, and compatible with a long list of applications. 
  • Covers most applications
  • Relatively simple installation
  • Includes everything needed to install
  • Compatible with ignition control 
  • Hands-off tuning process
  • Competitive pricing
  • Included fuel system may not work for some applications
  • Notoriously finicky
Best Value

FiTech Go EFI 4 600 HP System

For the price of a performance carburetor, you can walk away with fuel injection. This easy-to-install kit is a clear choice for many applications.  
  • Affordable
  • Pre-programmed to simplify setup 
  • Easy installation
  • Bolt flange works with many 4-barrel applications
  • No timing control 
  • Programming issues are relatively common
Honorable Mention

Edelbrock Pro-Flo 4 EFI Traditional 4150-Style Kit

Port injection offers optimal performance for any engine. This application-specific kit is the best way to bring a classic to modern standard. 
  • Port injection delivers precise fuel mixture for optimal performance
  • Compatible with ignition control 
  • Direct fit for application
  • Expensive
  • More complicated installation than cheaper options

Our Methodology

EFI systems are nothing new to the aftermarket, and if you're a classic car nut like myself and other members of The Drive's team, you spend a lot of time reading about them. Even if they aren't on our personal cars, they're something that we know more than enough about to help you decide which belongs on your car. That doesn't mean we view our minds as the only source of information. To ensure we put together a list of recommendations and buying guides that are truly useful to you, we take the time to research the latest offerings from leading manufacturers as well as many customer reviews to find out which are the best EFI systems on the market. 

Why Trust Us

Our reviews are driven by a combination of hands-on testing, expert input, “wisdom of the crowd” assessments from actual buyers, and our own expertise. We always aim to offer genuine, accurate guides to help you find the best picks.

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Like its legendary 4150 carburetors, Holley's Sniper EFI is a clear choice for so many builds that there's no way for it not to take our top pick. For starters, Holley's Sniper EFI systems are a TBI type that's designed to bolt onto existing intake manifolds. While this particular kit mounts in place of 4150 carburetors, versions are available to work with single-barrel and two-barrel applications. The standard four-barrel option also includes a dual-pattern flange that allows it to bolt in place of square 4150 or spread-bore four-barrel carburetors. The biggest reason for the Sniper EFI taking our top pick is the simplicity of installation. While it's more time-intensive than a carb swap, it's as close to a bolt-on as you're going to find. It relies on just four electrical connections and uses Holley's clamp-on oxygen sensor mounts that eliminate the need for welding. It's also a self-learning system, meaning you don't need to be a tuning expert to get it running. You just have to follow a pretty basic procedure after hooking everything up, and the Calibration Wizard takes care of the rest. Different kits are available to shorten the shopping process as well. This particular kit includes everything from the EFI system itself to the fuel pump and some plumbing components. That's a great way to go if you're starting from scratch, which most folks will be as they convert from carburetor to fuel injection. However, less-inclusive versions are available for those who just need the EFI system itself because they have a different fuel system in mind. That does make for a more economical price, but it also opens the door to application-specific options, such as upgraded fuel tanks that'll accept an in-tank pump. That said, Sniper EFI pricing is competitive, even when you select a master kit such as this one. Each Sniper setup will support different power ranges, but this is capable of feeding engines turning out up to 650 horsepower. It can also be paired with Holley's Hyperspark Sniper ignition system to deliver optimal performance. Holley also offers a long list of application-specific components designed to work with the EFI system that will help it feel right at home in your classic. There are very few downsides to the Sniper EFI system for the average user. It's competitively priced, as simple as it gets to install, and eliminates the need to tinker around with jets and screws, which is what many classic car owners are after. However, there are some issues you should be aware of. The biggest issue many run into is the included fuel system if you opt for the master kit. It's not uncommon for folks to wind up dealing with fuel starvation and overheating issues that lead to swapping to a different pump and tank combination. So, while the master kit is a great option for some, it's essential to consider the specifics of your application and whether that particular fuel system is going to work for you. Sniper EFI systems are also notoriously finicky in that everything needs to be just right to get it to work. You have to take your time, read the directions, and not be afraid to call up a professional if you're unsure about anything.

Other Product Recommendations  

Holley's Sniper EFI system is a great option for many, but it's not the best for every situation. Your build and personal preferences might require something else. That's why we included a list of alternative options below. 

Things to Consider Before Buying EFI Systems 

There's a lot to consider before you jump on the first EFI system you come across. Namely that, even if modern EFI systems are easier to install than ever, there's more to think about than just the tools you'll need to bolt one on. Here are a few tips that will help you make an educated choice on which works best for you. 

Key Features 


There are two primary types of EFI systems you can choose from. The first and most-likely choice is throttle body injection (TBI). These are the most simple and affordable types out there. This type works by placing the fuel injectors in the throttle body, creating a situation where a controlled mixture of fuel and air is pulled through the manifold. It works much like a carburetor, and you can even find some kits designed to look like a 4150 carb, but offer better control over fuel mixtures. Multiport injection is the other option. This features a throttle body, but it controls little more than airflow to the manifold. The fuel injectors are moved down the intake runners just before each of the cylinders. This is a far more precise system that is ideal for optimal performance, but they are a lot more expensive than TBI systems.

Power Level 

Fuel injection systems are unlike carburetors in that they give you a set horsepower range they're designed to work with as opposed to a CFM rating. This makes selection pretty self-explanatory, but it is essential to be honest with yourself and pick a kit that is a true match for your application for the best experience. 

Manifold Compatibility

Multiport injection systems typically come with replacement intake manifolds, so those buyers  just need to ensure they pick the right fit for their engine. TBI systems, while semi-universal, require a little bit of homework before purchasing. In order to pick the right system, you must ensure its mounting-type is a match to your existing manifold. Manufacturers offer kits to work with single, two, and 4-barrel setups. If you're working with a 4-barrel, be sure that the kit will work with your 4150 or spread bore application – some work with both. Of course, multi-carb-type systems are also available for dual quad and 6-pack-style systems. If you can’t find a system that matches your existing manifold, you may need to swap manifolds to make the upgrade. 


  • Fuel system upgrades are mandatory. EFI systems work on much greater fuel pressures than carburetors. You're going to need to make the upgrade to a fuel pump that can support your new EFI system and add a fuel-return line to the mix. Some EFI kits come with a fuel pump and plumbing to solve this issue, but it’s something to read into as you might need to come up with your own combination. 
  • Consider your ignition. Most EFI systems offer some type of ignition control system to help you get the most out of your investment. It's worth reading into your kit to verify whether or not ignition system upgrades are required or if they’re an option for your kit. 
  • Take your time. A lot of people get into this thinking it's a simple bolt-on swap, but it can be rather time intensive and is highly reliant on getting the details right. Make sure to follow the directions closely and give the project as much time as it needs. If you get confused or need help, manufacturer tech lines are a great source to fall back on.
  • Not a problem solver. An EFI system can only solve the problems it's designed to. It's not going to fix problems that aren't related to the fuel delivery system. If the heads are leaking, the rings are fried, or the engine needs an overhaul, you need to get that sorted out before you try to move to an EFI system. Otherwise, you might end up with more trouble than you started with
  • May need more juice. Don't be surprised if your factory charging system can't keep up with your EFI system, especially if you have other upgrades like aftermarket lighting and an aftermarket stereo system soaking up the supply. Remember that the factory alternators on classic cars only needed to supply power to a few accessories. You may need to upgrade to a more powerful unit. 


EFI systems alone usually cost anywhere from around $900 to $3000. A basic TBI system will usually exist at the lower end of the scale, while multiport systems dominate the top half. That price likely won’t cover everything, though. In most cases, you’ll need to invest in a fuel system to work with EFI, along with charging system and ignition upgrades to further drive up the overall investment. 


You've got questions. The Drive has answers.

Q: Is an EFI system better than a carburetor? 

A: Yes and no. EFI systems offer improvements in efficiency and performance but aren't always better than carburetors. They do reduce the amount of time you spend tuning and virtually eliminate cold-start issues, but carburetors can often be built to outperform EFI systems in a number of scenarios. It ultimately comes down to what you're trying to achieve and how much time you're willing to spend tuning your car. 

Q: How much horsepower does an EFI system add? 

A: That depends on how far off your carburetor is in the first place. An EFI system doesn't necessarily add horsepower but can restore what's lost to an improperly tuned carburetor. That doesn't mean you'll always pick up horsepower by making the swap, though.

Q: What do I need to install an aftermarket EFI system?

A: An EFI system can come with most of what you need to bolt it on. Some kits might even come with ignition and fuel system components. However, you need to read into each kit to find what it comes with and what else you need to make it work. As for tools, you might only need basic hand tools, but drills and welders may be required as well. Again, it depends on the kit you’re working with. 

Q. Will an EFI system improve fuel efficiency?

A. Yes. Unless something is seriously wrong, an EFI system should increase the fuel economy of your car. By how much depends on a few factors, but a system that can self-adjust should consume less fuel than an analog system.