Top 5 Best Spark Plugs For 4.3 Vortec (2020 Review)

Want to know the best spark plugs for the 4.3 Vortec engine, so you can be prepared for your next tune-up?

We've got you covered. In this guide, you will learn:

  • The best spark plugs for 4.3 Vortec engines
  • Tips for proper inspection and installation of spark plugs
  • Which spark plug wires are the best fit for your 4.3 Vortec

And much more!

Spark Plugs for 4.3 Vortec Engine
Image Product


NGK Iridium IX Spark Plugs
  • NGK Iridium offers high performance and longevity
  • Different options for performance
  • Reasonably priced
  • NGK Iridium offers high performance and longevity
  • Different options for performance
  • Reasonably priced
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Bosch Plantinum Spark Plugs
  • Best fuel economy
  • Pre-gapped
  • Super reliable
  • Best fuel economy
  • Pre-gapped
  • Super reliable
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Denso Platinum TT Spark Plugs
  • Comes in packs of six
  • Twin tip design for improved ignitability
  • Increased durability and minimized tip erosion
  • Comes in packs of six
  • Twin tip design for improved ignitability
  • Increased durability and minimized tip erosion
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Autolite Iridum XP Spark Plug
  • Wear-resistant V-trimmed platinum side wire technology
  • Better overall ignitability
  • .6 mm iridium fine wire electrode
  • Wear-resistant V-trimmed platinum side wire technology
  • Better overall ignitability
  • .6 mm iridium fine wire electrode
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ACDelco Professional Iridium Spark Plug
  • Excellent engine stability and smooth performance
  • Reliable cold starting and quick acceleration
  • Iridium fine-wire electrode burns off carbon deposits
  • Excellent engine stability and smooth performance
  • Reliable cold starting and quick acceleration
  • Iridium fine-wire electrode burns off carbon deposits
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Overall #1 Rated Pick

Updated As of 5/14/2020

Top Rated Overall:

NGK Iridium IX Spark Plugs

  • NGK Iridium offers high performance and longevity
  • Different options for performance
  • Reasonably priced

NGK is our top pick for the 4.3 Vortec engine because it provides top-quality performance at a reasonable price, and you can even purchase NGK plugs in packs of six on websites like Amazon. 

Want to use a product that is used in Formula One racecars? That's right, NGK doesn't mess around with their parts production. 

It is even said that NGK is turning its focus towards the production of solid-state batteries because electronic vehicles could eventually make spark plugs obsolete. Now there's a company that has its eyes on the future.

Are you working on a 4.3 Vortec? If it's a six-cylinder Chevrolet Silverado, Tahoe, Blazer or one of the GMC equivalents, then it's likely a Chevy small block engine like the Vortec.

Those six-cylinder Chevy engines are a hard engine to beat when it comes to getting the job done reliably. And any engine runs best when it is properly maintained. 

Below is a quick list of all our top products. Keep scrolling to learn more about how to find the best spark plugs and how to install them correctly.

Top 5 Best Spark Plugs for a 4.3 Vortec Engine

Check out our below list for a summary of our results. Keep on reading to learn more about your other options!

How To Change Spark Plugs On Your 4.3 Vortec?

If you don't already have the necessary tools, go to your local auto parts store and pick up these necessary items for servicing the spark plugs on your vehicle:

  • Spark plug socket and socket wrench
  • Wobble and extensions for hard to reach cylinders
  • Dielectric grease
  • Spark plug boot removal tool(needle nose pliers will work too)
  • Feeler gauges/gap gauge
  • Torque wrench

Changing the spark plugs on your 4.3 Vortec is something you can do yourself, and the first step is removing the old spark plugs to see if they are the cause of your misfiring problems. 

Note: It's important to take care of other outstanding repairs before replacing your spark plugs.

Chances are, if your spark plugs are fouled due to oil buildup on the tip then you have bigger problems on your hands. 

A few reasons why spark plugs foul are because of leaky valve covers, worn or damaged cylinders/piston rings, worn or damaged valve guides/seals, etc.

If you replace your spark plugs but they end up fouling again, that is when you know there is a bigger repair that needs to happen.

Just because your engine is misfiring doesn't mean you have a fouled spark plug. There are reasons why your engine could be misfiring, like a bad coil pack.

You may also want to inspect or change the distributor cap and rotor on your vehicle to ensure that it is functioning properly.

Changing the rotor cap out with the spark plugs is a good idea. Bad oxygen sensors also cause misfires. 

Inspection Tips: Carefully remove each spark plug and inspect the tips for fouling due to oil or corrosion. You can get a good idea for what a fouled spark plug looks like by doing a quick and easy google search, and you will also notice a misfiring fouled spark plug because it will look distinct from the other spark plugs.

Writing numbers on each spark plug boot with a bright-colored marker will help you remember which wire goes where. 

Inspect the top side of the plug that connects to the electrical connector for cracks in the white ceramic part. This can also cause misfiring and is a result of dropping the plugs or torquing them too firmly upon installation. 

If the spark plugs all check out visually and one cylinder is still misfiring, try reinstalling them and trading coil packs between cylinders to see if the misfire code changes to a different cylinder. Just make sure you reconnect the actual wires that go to the PCM in the same order always to avoid problems.

Read More >> How Do You Gap A Spark Plug Yourself?

Tips for Proper Installation

Gapping your spark plugs is easy with feeler gauges or a gap gauge. Find out what the correct gap is between the center electrode and the side electrode.

Most spark plugs are pre-gapped, but it never hurts to double-check the plug gap just to be sure. 

Blow out the cylinders with an air hose before installing the new plugs to be sure there is no debris inside the combustion chamber. 

You can also clean up the electrical connection on the spark plug boots by spraying them down with a little bit of alcohol.

Alcohol in a spray bottle is a great tool when working on vehicle electronics and piping because it cleans up connections and makes for easier removal and installation. 

Apply dielectric grease to the inside of the spark plug boots before connecting them back onto the spark plugs. This will ensure that each electrical connection is strong.

When replacing the spark plugs, try to slide them down into the cylinder head with the utmost of care.

Spin each plug tight with your fingers using the socket extension, and then torque each spark plug to spec with a torque wrench according to the manufacturer's specification. Normal spark plug torque spec is between 12-15 nm. 

You now have the basic knowledge of how to remove, inspect and install new spark plugs on your 4.3 Vortec. Get out there in the garage or driveway and have at it! 

Read More >> How Do You Check A Spark Plug Yourself?

Are There Different Types of Spark Plugs For 4.3 Vortec Engines?

Yes; Here are the main types of spark plugs based on metals used for conducting electricity

  • Copper
  • Platinum
  • Iridium

Heat Range

There are also different types of spark plugs for temperature and running conditions. This characteristic is called the heat range. 

For example, if you constantly run your vehicle in colder temperatures then you may want to opt for a hotter plug. On the contrary, if you like to rally your engine at high RPMs or run it in the desert then a colder plug is going to be the best bet. 

Manufacturers like Bosch and NGK have numbering systems that indicate the heat range of their spark plug.

Find out which number fits your driving conditions or habits better before purchasing your spark plugs for the best performance results. 

What Defines a Hotter or Colder Plug?

A hotter spark plug has more surface area on the insulator nose, allowing for more heat to be produced upon combustion. A colder plug has a shorter insulator nose with less surface area that inhibits excessive heat production.

Did you know: In 1986, Chevy created the first run of the 4.3-liter Vortec Chevy V6 engine. This quickly became one of the most commonly used engine in GMC and Chevy trucks.

How To Choose The Spark Plug Wires For 4.3 Vortec Engines?

Choosing spark plug wires on the web is an easy task to perform on any parts website.

Go to the website of your local auto repair shop or online parts distributor, and plug in your VIN to find all parts applicable to your 4.3 Vortec engine. 

If you want a personal opinion, call or visit a Chevy or GMC parts specialist located at a dealership who will be able to give you the best solution for which spark plug wires are best. 

How Long Should My Spark Plugs Last In My 4.3 Vortec Engine?

So long as there aren't any outstanding issues with your vehicle, your spark plugs should last for as long as the manufacturer intends them to.

Copper plugs have high conductivity and perform well but only last about 20,000 miles maximum.

Platinum and Iridium plugs can for 100,000+ miles so long as the engine is in good running condition and there are no oil leaks. 

Read More >> How Do You Remove A Broken Spark Plug?

My Reviews Of The Best 4.3 Vortec Spark Plugs

NGK is a company that is dedicated to making the best fitting spark plug for each specific engine.

When searching for NGK plugs, you will find that there are a few different options and price ranges which makes it an easy choice.

NGK plugs are starting to be more commonly the original part in Chevy and GM vehicles, plus they come in a six-pack on Amazon which is how many you'll need for the job.


  • OEM option
  • Free shipping on Amazon
  • High-quality


  • Foreign company
  • Hazards from flammable iridium dust
  • Risk of manufacturing error in precious metal layering

Products like Bosch Platinum and Iridium are some of the best options when replacing the spark plugs in not only the 4.3 Vortec but in any engine.

Bosch plugs are made with a quality that is hard to beat, with features like four yttrium-enhanced electrodes on the tip of the platinum version that gives them a futuristic look, and revolutionary performance enhancement. 

If you are looking to put the best parts in your 4.3 Vortec, then Bosch is a good choice.


  • Highest quality option
  • Revolutionary surface air gap firing technology
  • Four yttrium-enhanced electrodes


  • Higher cost
  • Foreign product
  • Performance enhancement may be unnoticeable

The Denso Platinum spark plugs are a steal when shopping on Amazon.

Car repairs can be expensive, and sometimes it's necessary to go with cheap and functional parts just to get a vehicle up and running.

You don't always need the best product to make the engine go. 

That's where Denso comes in to save the day, offering a six-pack of iridium spark plugs on Amazon for a price that is hard to beat.  

One good reason to go with the Denso plugs is that they come in packs of six which is exactly how many you will need to replace the whole set in your 4.3 Vortec.


  • Made in the USA
  • Unbeatable price
  • Comes in a six-pack


  • Possible manufacturing error of precious metal layering (because they are so inexpensive)
  • Iridium plugs are the same price

Autolite provides a high-quality solution for your spark plug replacement needs by providing you with products like the Autolite XP-104 Iridium spark plugs that are designed for performance.

There are plenty of five-star Amazon reviews where customers have improved the performance of their vehicles by installing Autolite plugs.

Autolite is also based out of the USA, so their plugs are a great choice for using an American part in a classic American vehicle.


  • High quality
  • 2-3 Cons
  • V-trimmed platinum side wire technology


  • Only comes in a four-pack
  • Iridium dust has a high risk of flammability
  • Higher cost

Don't forget about ACDelco when replacing spark plugs.  

Delco plugs have a suppressor seal that helps prevent combustion leakage, and the iridium fine-wire electrode is good at burning off carbon deposits to prevent fouling and misfires.

Check out ACDelco's Rapidfire spark plugs if you want a high performing OEM option. 

Support the economy of the United States by purchasing from a company that was founded and continues to operate in the USA.


  • Made in the USA
  • OEM Option
  • Iridium tip prevents misfires


  • Higher cost
  • Dust from iridium is flammable which can be hazardous
  • Unnoticeable performance enhancement is possible

NGK is our top pick because of their dedication to making great spark plugs. 

Although they may not be based out of the United States, NGK has headquarters for production in West Virginia, so you will still be supporting your local economy by purchasing from NGK. 

When compared to brands like Bosch and ACDelco, NGK gets brownie points for strictly manufacturing spark plugs.

Final Thoughts On Spark Plugs For 4.3 Vortec Engines

Now you have the brainpower to successfully maintain your 4.3 Vortec engine in your Chevy Silverado or another vehicle.

Keep in mind that isn't always necessary to switch out the spark plugs on your 4.3 Vortec. If you don't see any loss of efficiency or power, and the spark plugs check out visually with no engine misfiring then it's okay to keep the same set inside the vehicle. 

If you have removed the spark plugs for inspection and they are still good, then it is perfectly okay to replace the same ones into the vehicle. Just remember to replace parts like rubber o-rings that come on parts like oil filters and fuel injectors. 

Tips For Performance Enhancement

You're only going to see drastic performance enhancement by changing the spark plugs if your engine is misfiring or if the spark plugs are extremely old and corroded, so if you are looking to boost horsepower on your 4.3 Vortec you may want to consider changing out parts like the intake and exhaust headers. 

You can also install a performance-enhancing chip in your 4.3 that will drastically enhance your engine's performance.  

Read More >> What Sized Socket Should You Use For A Spark Plug?

Performing Spark Plug Service Yourself Vs. Professional Assistance

Wondering whether or not you should personally perform your maintenance on the 4.3 Vortec?

Here are some reasons why you should, and some situations when you should take it to the dealership or a professional mechanic for some tender love and care. 

If it's simply replacing the spark plugs for routine maintenance, then you should, by all means, empower yourself to perform the repair.

There isn't a whole lot that can go wrong when changing out the spark plugs if you tighten them down correctly and connect the wires how they were in the first place.

If you have oil coming off the top of your engine and notice that your spark plugs are also caked in oil upon inspection, then it probably means you need new valve cover gaskets.

This is a repair that you could also easily perform yourself with simple tools and a torque wrench. Distributor cap and rotor replacement is also a common problem that the 4.3 Vortec motor has that can be easily handled in the comfort of your driveway with simple tools.

Be sure to spray the engine off with degreaser beforehand to verify that the leak is coming from the valve covers, and to have a visual representation that you have solved the problem after the repair is done.

Keeping your engine clean is important when doing visual inspections and locating leaks. 

Are You Still Having Problems? Let a Pro Handle It

When it comes to the valves and cylinder problems that are making your spark plugs foul, it's time to leave the work up to a professional.

Chances are the amount you are paying for two sets of spark plugs could have paid for a quick engine diagnosis that could have kept the situation a bit more painless. 

Once you have a professional diagnosis of the problem that is causing your spark plugs to constantly foul, you will be able to decide on what to do next. 

In cases where your piston rings need to be replaced this means that your engine needs to be completely disassembled which can cost thousands.

You may want to evaluate the numbers because sometimes trading in your broken-down Chevy and purchasing a new one can end up costing you less than having expensive repairs performed.

Happy wrenching!

Read More >> What Are The Top Spark Plugs For 2-Stroke Engines?

About Your Mechanic

About Ryan Nichols

Ryan here! My pro mechanic career began as a technician for Mercedes-Benz. After two years of that great experience, I went out on my own in both the automotive and construction fields. I've since pulled my share of salvage yard parts and fixed more vehicles than I can count.

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