Ignition Coil & Iridium Spark Plugs & Wire Chevrolet Silverado 2500 HD 3500 HD (2020) 6.6L V8

High-Energy Ignition Coil & Iridium Spark Plug Kit for Chevrolet Silverado

Replaces failing factory ignition components to restore proper combustion, eliminate misfires, and improve throttle response under heavy loads.

The Stock Silverado L8T Heat Soak Problem

The stock Silverado L8T ignition system degrades over time due to intense thermal cycling under the hood, especially when towing or hauling heavy payloads. Continuous high-temperature exposure breaks down the factory coil epoxy and degrades spark plug electrodes, leading to increased electrical resistance. This manifests as weak spark output, engine misfires, rough idling, hesitation during acceleration, and inevitable Check Engine Light (CEL) or StabiliTrak/VSC warnings.Left unaddressed, poor ignition efficiency accelerates fuel waste and exhaust emissions.

The Engineering Solution

This comprehensive ignition overhaul kit is engineered to exceed OE specifications, delivering a 20% increase in spark energy and stepping up voltage to a maximum of 26,000 Volts (61:1 turns ratio). The UF742 coils feature premium internal copper windings and high-temperature epoxy construction to resist heat soak and heavy-duty vibration. Paired with 41-114 iridium spark plugs—chosen for their extremely high melting point and superior conductivity—this setup ensures a powerful, consistent spark event. The included 8mm spark plug wires utilize a high-density silicone sleeve and specialized heat shields to eliminate RFI electronic interference and prevent cross-firing, ensuring maximum voltage transfer directly to the combustion chamber.

Technical Specifications

Compatibility

• 2020 Chevrolet Silverado 2500 HD 6.6L V8 (Gasoline)
• 2020 Chevrolet Silverado 3500 HD 6.6L V8 (Gasoline)
• Replaces OE Coils: 12658183, 12621750, 12674754, 12699383, 12708496, 5C1876, U5265, 48881, C1819, C866, GN10165
• Replaces OE Wires: 748UU, 9748UU, 12633447, 12716289, 19431551, 7873
• Replaces OE Plugs: 41-114

The Chevrolet Heavy-Duty Standard

Designed to endure the grueling demands of heavy towing, payload hauling, and continuous job-site idling, these upgraded ignition components ensure your heavy-duty Silverado maintains optimal power delivery and reliability.

Common Questions

Will this ignition kit fit my 2020 Chevrolet Silverado 2500 HD or 3500 HD?
Yes, this kit is a direct fit for 2020 Chevrolet Silverado 2500 HD and 3500 HD trucks equipped with the 6.6L V8 L8T gasoline engine.

Does this kit work on the 6.6L Duramax diesel engine?
This ignition coil, spark plug, and wire kit is engineered specifically for the 6.6L V8 L8T gasoline engine.

What components are included in the box?
The kit includes UF742 high-energy ignition coils, 41-114 iridium spark plugs, and a set of 8mm silicone spark plug wires with integrated heat shields.

How do these coils compare to the factory Silverado HD coils?
These UF742 coils feature internal copper windings and high-temperature epoxy construction, delivering a 20% increase in spark energy and up to 26,000 volts with a 61:1 turns ratio.

Are any modifications required for installation?
Installation is a direct bolt-on replacement for your factory OE coils (such as 12658183 and 12674754), 41-114 plugs, and plug wires with no modifications needed.