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- USA
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Ships within 48 hours · Estimated delivery Jul 6 - Jul 11
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Description
Holley Coil-Near-Plug Smart Ignition Coils 556-128KIT, BIG WIRE 8 CYLINDER SMART COIL KIT Do you need precision control over your ignition system? Would your combination benefit from Individual Cylinder Timing Control? Are you experiencing spark issues with your Stock Coils? Are you wanting to convert your Turbocharged Big Block Monstrosity to Coil Near Plug?! Problem solved, introducing the Holley EFI Big Wire C N P Kit containing everything you need to upgrade your ignition system to handle 5. 5+
KIT, BIG WIRE 8 CYLINDER SMART COIL KIT
Do you need precision control over your ignition system? Would your combination benefit from Individual Cylinder Timing Control? Are you experiencing spark issues with your Stock Coils? Are you wanting to convert your Turbocharged Big Block Monstrosity to Coil-Near-Plug?! Problem solved, introducing the Holley EFI Big-Wire C-N-P Kit containing everything you need to upgrade your ignition system to handle 5.5+ HP per Cubic Inch
Features:
- “Big Wire” Sub Harness- Pre wired with 12ga Power and Grounds, for optimal performance!
- Peak Voltage – 44,000 Volts
- Peak Output – 102 Mj
- Maximum Battery Voltage 17.0 Volts
- Upgrading a Non C-N-P Main Harness requires the Holley Universal Coil-On-Plug Harness, P/N 558-307 to complete the installation!
- Contains two Terminated Sub-Harnesses, and Eight Holley Smart Coils, 3 ft. of wiring loom for a professional appearing installation!
- Sub Harness features Fully Terminated Coil Connectors, a 7 Pin Metripak Connector used on several Holley EFI C-N-P Main Harnesses, and 3 loose wires for a quick installation!
Application
-
Universal
Specs
| Brand | Holley EFI |
|---|---|
| Emission Code | 4 |
| Height | 1.86" |
| Ignition Wire Terminal Type | HEI Style Tower |
| Mounting Bolt Pattern | 74mm |
| Overall Length | 4.3" |
| Product Type | Distrutorless Ignition - DIS - smart coil |
| Width | 3.6" |
| Part Number | 556-128 |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.4 ★★★★★
Based on 72 reviews
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Product Reviews
★★★★★ 5
It’s good
Size: 300A Fuse Holder
It does it’s job.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 18, 2026
★★★★★ 4
Cover too loose.
Size: 300A Fuse Holder
Nice looking, decent quality, versatile for different gauges. My only complaint with this holder is the cover doesn’t stay on very well, bought 3, and all 3 pop off easily, you will need to zip tie on.
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Reviewed in the United States on January 12, 2026
★★★★★ 5
Works as it should.
Size: 300A Fuse Holder
I’ve had several of these in my build for over a year now. Zero issues.
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Reviewed in the United States on December 3, 2025
★★★★★ 5
Good brand
Size: 300A Fuse Holder
Good product
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Reviewed in the United States on November 5, 2025
★★★★★ 5
Rock-Solid Mounts with Flawless Adjustability
Size: Standard--black, Size: Standard--black
Absolutely fantastic mounts! I couldn't be happier with this purchase. They are currently holding my 12lb surround sound speakers on the wall, and I have complete confidence in their sturdiness. They feel incredibly solid and well-made.
Installation was a breeze, and the range of motion is a real game-changer. Being able to swivel and tilt the speakers has allowed me to perfectly angle them towards my listening position, which has made a huge difference in my surround sound experience.
On top of the great functionality, they have a very sleek and clean look. The built-in cable management is a brilliant touch that helps keep everything looking tidy and professional.
If you're looking for a reliable, adjustable, and great-looking set of speaker mounts, look no further. These are top-notch, and I highly recommend them!
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Reviewed in the United States on July 30, 2025