What is the Best HEI Distributor for 350 Chevrolets? I dug in and spent hours talking to pros, doing the research, and figuring out the differences between the competing models.
HEI — or High Energy Ignition — refers to the design introduced by GM in 1974 that combines the ignition coil with the distributor.
The more compression you have and the higher the RPMs that you run, the more important it is that you have a dialed-in Distributer system.
The correct distributor eliminates engine hesitation and gives you the most power possible.
As with most of these vehicle upgrades, there are entrenched fans on each side. Each side makes valid points, and it can become overwhelming.
If you feel overwhelmed by the terminology, I’ve also put together a buyer’s guide down below the product reviews. Scroll down there, first, for more background information so you can make an empowered decision.
Best Distributors for Chevy Small Block
MSD 8551 Pro Billet Distributor
If you want the power of a High Energy Ignition system but are struggling to find enough space in the engine block for the larger cap size, this MSD system is exactly what you are looking for.
This is also MSD’s professional racing line designed for sustained, high-RPM use.
The thing that sets MSD apart is its multiple spark sequence that keeps the spark plug firing for 20 degrees of rotation longer than most distributors. This ensures a complete burn of fuel, prolonging your engine’s life and delivering the most power possible.
The outside of this model uses a higher quality 6061 aluminum that has been CNC machined. Inside of that is a hardened steel drive shaft with ball bearing support on one end and a sintered bushing on the other.
Most companies stop there, but MSD goes further with their Quench Polish Quench (QPQ) coating that removes friction and heat, creating an ignition system that will outlive most of its owners.
This delivers reliable performance at all RPM ranges to guarantee a perfect throttle response.
This system is designed for racing and does not accept an advanced vacuum canister.
Additionally, to facilitate the smaller size, this one will require some added parts: you must also purchase the ignition module and control box separately.
This kit is designed for the high-performance engine, where you need to be able to adjust the timing and get the advance curve dialed-in perfectly. It’s especially nice that it works in tight places that don’t have the clearance for a standard HEI kit.
MSD Street Fire Kit
If you have room for a full-sized HEI distributor, this is the kit to go with. You still get that MSD engineering that includes the multiple-spark sequence on each rotation, but in an affordable, street-racer package.
However, with this all-in-one kit, you have everything you need. The ignition coil is built into the head of the distributor cap and delivers 40,000 volts of consistent power.
I love this kit because it gives the budget-minded enthusiast access to real power and offers a taste of what the pros get. If you are hoping to race, you should step up to the Pro-Billet line as it has the additional hardening required to sustain high RPMs for long periods of time.
This kit also includes the vacuum advance port, making it ideal for those who want to boost the sub 4,000 RPM range performance.
This kit also includes low-impedance plug wires.
I realize that this kit costs a little more. However, if you are tired of fighting with your car’s performance and just want reliable turn-key performance that will let you race off the stoplight, this is the one I would choose.
Accel Chevy V8 With Vacuum
Two brands are at the top when it comes to distributer shopping. The first is MSD, and right up there with them is the Accell brand.
When you hold one of these and one of the cheaper imports, the thicker construction is immediately evident.
This one is designed to perfectly replace your OEM parts. The cast aluminum housing is quite durable, and the long sintered bushings give you the longevity you are looking for. It’s plug-and-play ready for your engine.
This model includes a vacuum connection but is not adjustable. Of course, if you don’t have a vacuum setup, simply leave this feature capped.
The coil is included with this model cutting down on the parts you need to buy.
If you’ve been drooling over the MSD, but the budget won’t support it, this Accell is perfect for daily driving and street racing. Assembled in the USA and backed by a one year warranty.
Assault Racing Small Block Chevy
Assault racing makes good automotive products that are well trusted. I had to dig to find this one online but was super excited to see that Amazon has their products.
Assault Racing specializes in selling products for the motor enthusiast who wants nice products without spending too much money. Likely, you’ve already bought a valve cover or air filter cover from them.
This model uses a fully CNC Machined aluminum housing. This precision construction means that all of the edges are smooth and burr-free and slips in nicely into the OEM spot. It also helps to create a tighter seal to prevent oil leaking.
A lot of folks talk about how their car runs smoother. The housing is thick and well-built, so you don’t get those annoying failures at 500 miles (like some of the cheaper Chinese import models sometimes are prone to do.)
With a 65,000 volt super coil, this one lives up to the high energy name. You get a consistent spark the will make even the oldest Camaro or Firebird sing it’s way down the highway.
The 4-pin GMC connection makes it easy to get it up and running.
It almost seems too good to be true, but it has the durability to make it my favorite for the Chevy 350.
Bravex HEI Distributor SBC/BBC
Most of my readers are just looking for an affordable way to swap out their old distributor cap on their daily driver or farm truck.
This Bravex/ACPulse/Steinbrucke model offers longevity and daily-driver performance. When you are trying to beat that semi onto the freeway, this is an excellent ignition system to go with.
Bravex has found a unique niche in the automotive aftermarket parts industry. In business for over a decade, they produce winches and fuel pumps, but their ignition line up is what seems to be attracting attention.
Their affordable redcap distributor is the closest thing to a one-size-fits-most that I’ve come across as it is compatible with multiple GM engines, including the big block 454 engines.
This is a complete distributor that includes the rotor, the cap, and the coil that creates the spark.
The high output coil dwarfs most of the others in its class.
It delivers 65,000 volts of spark with as little as 7,500 RPMs but jumps up to 75,000 volts as the car approaches 9,000 RPMs. For racing with the throttle wide open, this ignition system is designed to keep up.
The steel cam interfaces easily with your engine, and the standard 4-pin GM connection makes this an extremely easy upgrade, even on those older 1965 projects.
The frustrating thing with this distributor is that it is sold under multiple names. However, it seems to hold up well and is easy to install. Good for Small Block Chevy (SBC) and Big Block Chevy’s (BBC).
A-Team Affordable Performance Complete Distributor
If the MSD reviewed above was more expensive than what you were hoping to find, this model from A-team will fit the bill perfectly.
This Chevy 350 distributor is designed with the smaller cap that will fit into tight places between the firewall and the carburetor.
This one has brass connectors that make it easy to connect it to the spark plugs and offers the little holding tab to hold the wires in place.
The multi-pole magnetic sensor detects what position the rotor is in and triggers the firing signal. It connects to your existing wiring harness with a standard two-wire connection.
You’ll need to buy a separate coil to power this model. They recommend one that produces 35,000 volts. The nice thing about this lower voltage is that you don’t need to re-gap your spark plugs.
They sell a nice coil/distributor combo kit that I recommend.
It also allows for Vacuum Advance. If your car doesn’t already have the vacuum advance, you can just cap this off.
For those of you fighting tight spaces, the A-team performance distributors are an affordable option.
MOSTPLUS Racing SBC HEI Distributor Cap Replacement
This MOSTPLUS Racing cap is another excellent replacement if you are looking to upgrade your daily driver. It’s designed to fit the 305, 350, and 400 series small blocks.
This is an OEM cap where the wires criss-cross. This makes it easy to plug-and-play without messing up your timing. Just make sure the rotor is started in the proper position and that the engine isn’t turned over while you are installing the new one.
The components aren’t racing-level but seem to hold up ok. The steel rotor integrates perfectly with your car’s standard setup, which makes installation easy.
It also comes with an adjustable vacuum advance.
The challenges are that this distributor seems to be made of a thinner material and is more likely to crack. It is an extremely affordable option, but may not be the most durable. Choice.
Pertronix Flame-Thrower Distributor Cap And Rotor
Sometimes you just want to fix your stock GMC distributer. You don’t need to install an entirely new rotor that connects to the camshaft.
Instead, just replace the cap and rotor.
I was never much on filing points, and replacing the cap and rotor was how I used to repair old-style distributers.
With this kit, you just replace the two parts most likely to wear out. You get a larger air gap around the coil to prevent arc-through, and it is made from a 60KV rated molding compound for longevity.
If you’ve bought another brand and are frustrated with how thin and easily cracked the plastic is, this an easy upgrade. Just move the ignition module over to this kit and install it.
If you want to save some money while only using top-notch parts, this kit will fix the most common distributor problems.
Here is some general overview information on HEI Distributors to help you understand what makes one choice better than another.
What is an HEI Distributor?
HEI means high energy ignition. This refers to the electric ignition used to deliver a spark to the spark plugs. HEI distributors refer specifically replacements for the 1974 to 1980 GM distributor cap design.
They often deliver more power. This higher voltage may allow you to open the gap on your spark plug and create a large flame for complete combustion.
HEI vs Points Distribution
Should you add an electronic conversion kit to your classic car’s ignition system?
When points are brand new and well adjusted, they run well. You need to adjust them regularly and replace the distributor when the points get too worn.
One of the easiest ways to switch from points to an electrical ignition system is with a conversion kit. These kits replace the points in your existing distributor and are an affordable way to reduce maintenance and are a great choice for a daily driver.
However, if you have room for the larger HEI distributor cap, you can greatly improve your car’s performance by going with a high energy ignition system. Additionally, starting in 1974, HEI was commonly found on small block GM products.
Symptoms of a Bad Distributor
The symptoms of a bad distributor are very similar to the symptoms of bad spark plugs. The car will sputter and struggle to start (hard starting), have a reduction in fuel economy, or illuminate a check engine light with a misfire code.
Most folks start by replacing the spark plugs, and wires as those are relatively cheap and easy to replace.
- No Spark: One way we used to test these was to unscrew a spark plug, disconnect the fuel pump, and turn over the engine, looking for a spark at the tip. No spark can indicate a bad hot wire from the positive side of the battery to the ignition coil, or a bad connection from the ignition coil to the distributor cap. Or, it can indicate a bad point inside the distributor or a cracked distributor cap. Technically, you would need to repeat this test with all eight spark plugs. An easier option is to use an ignition tester.
- Failure To Start: This can indicate a bad ignition coil or a bad distribution cap.
- Failed Emissions Test: An excessive amount of hydrocarbons in a smog test can indicate unburned fuel that is a result of one or more cylinders, not firing. Even if you only have one bad point in the distributor cap.
Does an HEI Distributor Need A Vacuum Advance?
Vacuum advance runs a vacuum line from the intake manifold to the Distributor cap (simplistically). Under idle and partial throttle conditions, the vacuum advanced adjusts the timing based on the amount of air being drawn in.
This can create a smoother idle and improve how quickly the vehicle accelerates.
However, once you move to a full-throttle state, the mechanical timing takes over and controls the distributor cap.
Accordingly, these are the best option for cars that mostly run in partial throttle conditions (street use) as opposed to racing use where the throttle is full-open.
Some HEI distributors are compatible with vacuum advance (sold separately for $30+).
One thing to watch for is cheap made-in-china imports. Some of these brands use super-thin plastic that may crack after a couple of years of use. That’s one reason why I’m inclined to spend over $100 as the quality tends to be a little better in this range. Don’t hesitate to call the manufacturer and make sure they have a good customer service department.
For daily driving, I’m very impressed with the Accel and the Assault Racing models. They seem to offer the durability you want with the voltage that will create a smoother ride and a little more power.
However, if you want to show up to the local drag strip, the MSD Pro-Billet is going to be hard to beat.
About Zachary Drumm
Hey! My name is Zachary Drumm! This site allows me to try these tools out, piddle around in the garage, and create fresh content for you. When it comes to tools, home improvement, and being a “shade tree mechanic,” you’ve come to the right spot.