Best Spark Plugs For 350 Chevy Featuring 5 Quality Options

Man, if you own a classic small block 350 Chevy, you know finding the right parts is crucial for maximizing performance. I’ve spent countless hours tuning these engines, and I can tell you that the right spark plug makes a massive difference in throttle response and fuel economy. We’re going to dive deep into the best spark plugs for 350 Chevy engines, comparing five top-tier options—from reliable conventional plugs to performance-focused designs—to help keep your trusty SBC running smoothly.

IMAGE	PRODUCT NAME	AMAZON LINK
	ACDelco CR43TS 5614029 (05614029) Professional Conventional…	View on Amazon
	R45ts Pkg 8	View on Amazon
	8 pc NGK 6630 V-Power Spark Plugs for 1052895W 15…	View on Amazon
	ACCEL 8198 Performance U-Groove Header Spark Plug – Pack…	View on Amazon
	AC Delco R45TS Spark Plug Set of 8 for Chevy…	View on Amazon

ACDelco CR43TS 5614029 (05614029) Professional Conventional Spark Plug BOX OF 8

These ACDelco CR43TS plugs are a fantastic choice if you want reliable, factory-style performance without breaking the bank. ACDelco plugs are trusted OEM components, and this conventional plug uses a robust copper core designed for effective thermal transfer, which is key for maintaining proper engine temperatures in your small block 350. They are built to resist misfires thanks to the ribbed suppressor seal, giving you confidence whether you’re cruising or putting your foot down.

Key features that stand out:
– Copper core thermal properties provide great heat transfer and increased plug durability.
– Features a ribbed suppressor seal which extends resistance and prevents spark flash-over and misfire.
– Black onyx coating helps prevent corrosion, especially important in older engine bays.
– Available for use in marine applications, showing their environmental robustness.

Pros:
– Excellent heat dissipation due to the copper core.
– Highly reliable conventional design suitable for most stock or lightly modified 350s.
– Strong corrosion protection.

Cons:
– They require replacement more frequently than iridium or platinum plugs.

Best for:
Stock or mild performance 350 Chevy engines requiring dependable, conventional operation.

Expert Opinion: For standard applications, the CR43TS is often considered the gold standard. Its design focuses purely on reliable, clean combustion, which is exactly what a daily driver or weekend cruiser 350 needs.

R45ts Pkg 8

The R45TS plug configuration is practically iconic in the SBC world, known for its wide fitment range and conventional reliability. This package provides that classic, proven performance with modern enhancements to durability. The combination of the copper core and the specific metal alloys ensures maximum heat conductivity while resisting oxidation over time, meaning better longevity than older conventional plugs.

Key features that stand out:
– Copper core thermal properties provide great heat transfer and increased plug durability.
– Nickel-chrome alloy sheathing to help prevent corrosion on the center electrode.
– Black onyx coating helps prevent corrosion on the shell.
– Available for use in Marine applications, highlighting durability.

Pros:
– Very popular and proven heat range for the 350 Chevy.
– Excellent resistance to corrosion due to multiple coatings.
– Cost-effective maintenance solution.

Cons:
– Not designed for extreme high-compression or forced induction setups.

Best for:
Enthusiasts seeking the original conventional plug standard for their 350 restoration or mild modification project.

Expert Opinion: The R45TS remains a staple because it simply works. It’s tough to beat this plug when you want OEM-level performance and heat control for a carbureted 350.

8 pc NGK 6630 V-Power Spark Plugs for 1052895W 15 16 1765179 18 1835800T 1835906T 18C2 18S 19 25 25BP 25C2 25DP2 25S 26 2R45TS 2R46TS 3851859 3851861 44TS 45TS 46TS 5020 5024 5025 5026 5213202S 577

NGK is renowned globally for its quality ignition components, and the 6630 V-Power plugs bring a subtle performance edge to the conventional design. The V-Power design features a unique V-groove cut into the center electrode, which directs the spark to the edges of the electrode, creating a hotter, more concentrated spark. This results in superior ignitability and potentially faster flame propagation, beneficial for overall engine efficiency and slightly enhanced horsepower.

Key features that stand out:
– 8 pack NGK V-Power 6630 Spark Plug ensures a complete replacement set.
– V-Power groove provides a sharper spark, improving ignition performance.
– Genuine NGK Parts providing known quality and consistency.
– Direct replacement auto parts simplifying installation.

Pros:
– Improved ignitability over standard conventional plugs.
– Better resistance to fouling thanks to the enhanced spark path.
– Excellent build quality characteristic of NGK products.

Cons:
– Requires careful gap setting right out of the box for optimal performance.

Best for:
Small block 350 owners looking for a minor performance upgrade using a reliable, widely respected conventional plug technology.

Expert Opinion: NGK’s V-Power series is an excellent compromise between the cheap reliability of a standard copper plug and the higher cost of a performance platinum plug. The V-groove genuinely assists in achieving a cleaner burn, which is crucial for older engines.

ACCEL 8198 Performance U-Groove Header Spark Plug – Pack of 8

If your 350 Chevy is built for speed and sports header pipes, you know how crucial clearances are. The ACCEL 8198 plugs are specifically engineered with a shorter profile to accommodate tight engine bays and performance headers. Beyond fitment, these plugs are built to deliver high-RPM power and instant throttle response, meaning they are ready for heavily modified or race-built SBC engines. The U-Groove design helps reduce quenching, leading to a much more efficient spark.

Key features that stand out:
– Ideal for use in cramped spaces due to their short design, perfect for engines with headers.
– Deliver significantly more power at high RPM.
– Instant throttle response and better fuel economy than fouled plugs.
– Less fouling, flame dissipation, and misfire due to the U-Groove design.

Pros:
– Exceptional performance benefits for modified engines.
– Shorter plug height solves common header clearance issues.
– Optimized for quick ignition during hard acceleration.

Cons:
– These plugs may run hotter than conventional plugs in stock applications, requiring careful tuning.

Best for:
Highly modified or racing 350 Chevy engines running high compression or facing clearance issues due to performance exhaust headers.

Expert Opinion: ACCEL plugs have always targeted the high-performance market, and the U-Groove design here is meant to maximize the flame kernel size. If you’re running a hotter ignition system and frequently hit high RPMs, these are engineered for your use case.

AC Delco R45TS Spark Plug Set of 8 for Chevy GMC Buick Cadillac Pontiac Olds

This is another classic, widely compatible option for those seeking the standard AC Delco reliability that the small block 350 was built on. The R45TS heat range is perfectly suited for the factory specifications of most vintage Chevy engines, providing consistent start-up and smooth idle. When you’re dealing with an older motor, sometimes sticking to the original equipment standard is the wisest choice for guaranteed compatibility and long-term running stability.

Key features that stand out:
– Standard R45TS heat range suitable for a massive array of 350 Chevy applications.
– AC Delco OEM quality ensures reliable performance and fitment.
– Set of 8 provides everything needed for a full tune-up.
– Designed for compatibility across many vintage GM vehicles.

Pros:
– Unmatched compatibility and factory-specified reliability.
– Excellent choice for restoration or pure stock engine builds.
– Consistent performance across wide temperature ranges.

Cons:
– Offers no performance advantages over the original conventional design.

Best for:
Owners prioritizing reliable, stock-like operation and those doing period-correct restorations on their 350 SBC.

Expert Opinion: If someone asks me what plug guarantees they won’t have problems in a stock 350, I almost always point them to the R45TS. It’s the definition of ‘set it and forget it’ reliability for this engine.

Comparison Insights

When choosing the best spark plugs for 350 Chevy, your decision really comes down to application. If you have a completely stock or mildly tuned engine, the conventional R45TS or CR43TS plugs from ACDelco offer the best balance of cost and reliable operation. They manage heat beautifully in standard small block setups.

However, if you’re chasing better ignition, the NGK V-Power 6630 is an excellent mid-range upgrade, providing a more efficient spark for only a slight increase in price. For those with high-performance modifications, especially headers and high-revving cams, the ACCEL 8198 is specifically designed to handle the increased heat and tighter physical constraints, making them the clear performance choice.

Remember that conventional copper plugs offer the best conductivity but have the shortest lifespan, meaning they’re great for performance and older systems but require more frequent changes.

Final Verdict

Making a final call on the right plug for your 350 depends entirely on what your engine is doing.

If you’re driving a mild street machine or cruiser: Go with the ACDelco CR43TS. You’ll get robust conventional performance, excellent corrosion resistance, and decades of proven reliability without the need for advanced tuning.

If your 350 is built for performance (high compression/headers): The ACCEL 8198 is worth the investment. Its unique design solves clearance problems and optimizes the spark for high-RPM demands, directly improving power output and throttle response.

For the best all-around upgrade blending reliability and efficiency: Choose the NGK 6630 V-Power. It takes the proven conventional design and adds a spark enhancement that benefits fuel economy and starting performance in a wide range of applications.

Best Spark Plugs For 350 Chevy FAQ

What is the correct spark plug gap for a 350 Chevy engine?

The standard spark plug gap for most small block 350 Chevy engines (SBC) running a points-style distributor is typically around 0.035 inches. If you have upgraded to an HEI (High Energy Ignition) system, you should typically widen the gap to 0.045 inches, as the hotter HEI spark can easily jump that larger distance. Always consult your engine manual or ignition system manufacturer for specific recommendations.

Should I choose copper, platinum, or iridium spark plugs for my 350 SBC?

For a classic 350 Chevy, copper is almost always the best choice, especially for carbureted engines. Copper has the highest conductivity, which is essential for maximizing the power of older ignition systems. While platinum and iridium last much longer, their smaller electrodes (designed for modern computerized ignition) often don’t provide a sufficiently robust spark for older, conventional systems.

How often should I replace the spark plugs in my conventional 350 engine?

If you are using conventional copper plugs (like the R45TS or CR43TS), they should typically be inspected and replaced every 10,000 to 12,000 miles. Copper wears down faster than precious metals, but replacing them frequently ensures peak small block 350 performance and prevents misfires and fouling.

Are there specific heat ranges required when choosing the best spark plugs for 350 Chevy performance applications?

Yes. If you have significantly increased the compression ratio or are running forced induction (turbo/supercharger), you should opt for a “colder” plug. A colder plug transfers heat more quickly to the cylinder head, preventing pre-ignition. Conversely, a stock engine needs the standard heat range (like the R45TS) to avoid fouling.

Does the short profile of the ACCEL plugs impact performance?

The short profile of plugs like the ACCEL 8198 is primarily for fitment, allowing clearance around large performance headers. However, their internal structure and the U-Groove design are what deliver the performance benefits at high RPM, optimizing the spark without sacrificing ignitability, which is crucial for maximizing 350 Chevy horsepower.

What are LSI keywords and why are they relevant to 350 Chevy plugs?

LSI (Latent Semantic Indexing) keywords are related terms that help search engines understand the full context of the main topic. When discussing the best spark plugs for 350 Chevy, relevant LSI terms include SBC engine, spark plug gap 350, AC Delco conventional, HEI ignition, and small block 350 horsepower. Using these naturally helps the article rank for broader, related searches.