If you own or work on a Ford 390 FE engine, choosing the right spark plug directly affects how the engine starts, runs and uses fuel. Correct plug reach, heat range and ignitability help you avoid fouling, improve throttle response and maintain smooth idle.
These two NGK V-Power options are common, affordable replacements that fit the 6.4L/390 era engines and give you a simple way to keep the engine reliable and efficient.
Top Picks
| Category | Product | Score |
|---|---|---|
| 🏆 Best Overall | NGK V-Power Spark Plug WR5 (8 Pack) for FORD CUSTOM 1964-1971 6.4L/390 | 88/100 |
| 🎯 Best for Classic Mustangs | NGK V-Power Spark Plug WR5 (8 Pack) Compatible With FORD MUSTANG 1967-1969 6.4L/390 | 92/100 |
How We Picked These Spark Plugs
You want plugs that match the Ford 390 FE’s reach, heat range and thread size while delivering dependable ignition. We looked at compatibility with 6.4L/390 applications, core and tip materials (copper core, nickel/metal tip), electrode design and specific features like NGK’s V-Groove ignitability.
Durability, resistance to fouling, manufacturer heat range, physical reach (0.460 in) and wrench size were considered so the plugs seat and perform correctly in older heads. We also weighed customer feedback and value — you need something affordable that actually improves starting, throttle response and fuel burn without fuss during installation.
NGK V-Power WR5 (8 Pack)
If you’re working on a Ford 390 FE, these NGK V-Power WR5s are the kind of plug that feels like a sensible, no-nonsense choice. The V-Groove design lets the spark form at the edge of the center electrode so the flame kernel grows faster — in practical terms that usually means crisper ignition, smoother acceleration and a small improvement in fuel burn.
They’re built with nickel-alloy tips and a copper core, and NGK’s trivalent plating helps resist corrosion and seizing so they’re easier to remove later. For daily driving you’ll notice steadier throttle response and reliable starts; for weekend classics and occasional spirited runs they hold up well to electrical and chemical wear.
A practical tip: inspect each plug before installation (some users found damaged ceramics in a few packs). Overall, if you want OEM-approved replacement performance without overcomplicating your tune-up, these are worth considering.
Pros and Cons
| Pros | Cons |
|---|---|
| ✅ Improves ignition and throttle response | ❌ A small number of users reported cracked ceramic insulators on arrival |
| ✅ Durable construction with anti-corrosion plating | ❌ A few users experienced poor performance and preferred other brands |
| ✅ OEM-approved fit for Ford 390 FE | |
| ✅ Sold in an 8-pack so you can service the whole engine |
What People Say
Many owners report smoother running and better throttle response after swapping to these NGKs, while a few buyers warn to check every plug for cracked ceramics before installation.
Overall Sentiment: Positive
🗣️ Amazon Customer
Made truck run better.
Brand Trustworthiness
NGK is a long-established ignition parts maker with widespread OEM and aftermarket use, so you can feel comfortable relying on their engineering and manufacturing standards.
Problem Solving
These plugs address common running issues like weak ignition, hesitation and reduced fuel efficiency by improving spark consistency and resisting fouling.
Key Benefits
- V-Groove design for quicker, more efficient ignition
- Improved ignitability and lower voltage requirements
- Durable against electrical and chemical wear
- Trivalent plating reduces corrosion and seizing
- Compatible with Ford big block FE 6.4L/390 engines
Rating: 4.0 (total: 11+)
NGK V-Power WR5 (8 Pack)
If you’re tuning or maintaining a Ford 390 FE, these NGK V-Power WR5s are a straightforward, dependable option. They use a copper core with a nickel-alloy tip, so you get solid conductivity and predictable wear characteristics rather than exotic longevity claims.
In daily driving you should notice consistent starts and a steady throttle feel; for weekend cruising or light spirited runs they hold up well to normal electrical and chemical wear. They come as an 8-pack so you can change the whole engine at once, and their OEM-compatible fit makes installation painless.
A practical note: inspect each plug before fitting and gap them to your engine spec. If you want an easy, OEM-style replacement that won’t overcomplicate your tune-up, these are worth considering.
Pros and Cons
| Pros | Cons |
|---|---|
| ✅ Straightforward OEM-compatible fit for Ford 390 FE | ❌ Nickel/copper construction means shorter service life than iridium or platinum options |
| ✅ Good conductivity thanks to copper core | ❌ Comes only as an 8-pack — not ideal if you need a single plug |
| ✅ Durable under normal use and easy to install | |
| ✅ Comes as an 8-pack so you can replace all cylinders at once |
What People Say
You’ll see reviewers saying the plugs improved running — one buyer summed it up as “Made truck run better.” With a small number of ratings, the feedback points to reliable, no-fuss replacement performance.
Overall Sentiment: Positive
🗣️ Amazon Customer
Made truck run better.
Brand Trustworthiness
NGK is a long-established maker of ignition parts with a strong OEM and aftermarket presence, so you can rely on consistent manufacturing and fitment.
Problem Solving
These plugs help address common issues like uneven idle, weak starts and inconsistent throttle response by restoring a consistent spark and reliable combustion.
Key Benefits
- Economical, OEM-style replacement performance
- Copper core for reliable conductivity
- Durable against standard electrical and chemical wear
- Sold in an 8-pack so you can service the entire V8
- Compatible with Ford big block FE 6.4L/390 engines
Rating: 5.0 (total: 2+)
FAQ
Are NGK V-Power WR5 Spark Plugs Right For My Ford 390 FE?
You can use NGK V-Power WR5 plugs in many Ford 390 FE setups because they match the common 18mm thread and the 0.460 in reach used on stock heads , and they come as a resistor-type plug with V-Groove technology that helps ignitability and a more complete burn. (These are for stock iron FE heads; many aftermarket aluminum FE heads use 14mm x 0.750 in gasket-seat plugs, so confirm your head spec before ordering.) They work well for stock engines and mild performance builds, but if you run a high-compression motor, forced induction, or want the longest service life you may prefer platinum or iridium alternatives; also make sure you order the correct part number for your application and inspect each plug before install for cracked ceramic or manufacturing defects.
How Should You Install And Gap These Plugs For Best Performance?
You should gap the plugs to your engine’s tune-up specification — commonly between 0.030 and 0.045 inch for older Ford V8s — but always follow your vehicle service manual for the exact gap and ignition timing. Install one plug at a time to avoid dropping debris into the cylinder, confirm the reach matches the original (0.460 in) so you don’t alter combustion chamber geometry, and tighten to the manufacturer torque spec using a torque wrench; if you consider anti-seize, apply it sparingly and adjust torque accordingly or follow NGK’s guidance to avoid over-torquing.
What Maintenance And Troubleshooting Tips Should You Know?
You should check plugs during routine tune-ups because these copper-core nickel-tipped plugs provide good ignitability but generally require replacement more often than iridium or platinum types; look for fouling, heavy carbon deposits, oil contamination, an unusually large gap, or cracked ceramic as signs of trouble. If you see misfires, rough idle, or poor acceleration, rule out ignition wires, coil and timing first, confirm correct heat range (the WR5 is a mid-range heat number) and replace all plugs at once for consistent performance, keeping an eye out for counterfeit parts by verifying part numbers and reputable sellers.
Customer Favorites
You prefer the NGK V-Power WR5 because it gives reliable ignition, the right heat range for a Ford 390 FE, consistent long life and a convenient 8-pack that makes servicing multiple cylinders simple. When choosing between similar listings, you typically focus on authenticity and correct part number, proper gap and packaging condition, and price or seller reputation so you’re sure you’re getting genuine NGK performance.
Wrapping Up
Both options are NGK V-Power plugs built around the same V-Groove design that improves ignitability and resists fouling. If you want the best-balanced choice for most 390 FE rebuilds or tune-ups, go with the Best Overall pick; if you specifically restore classic Mustangs and want a highly rated fit, consider the Mustang-compatible pack.
| NGK V-Power Spark Plug WR5 (8 Pack) for Ford Custom 1964-1971 6.4L/390 | NGK V-Power Spark Plug WR5 (8 Pack) Compatible With Ford Mustang 1967-1969 6.4L/390 | |
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| Rating | 4.0/5 (11 reviews) | 5.0/5 (2 reviews) |
| Weight | 1.19 pounds | 1.2 pounds |
| Dimensions | 3.31 x 0.94 x 6.64 inches | 3.31 x 0.94 x 6.64 inches |
| Core Material | Copper | Copper |
| Buy Now | Buy Now |
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