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

High-Energy Ignition Coil & Iridium Plug Kit for GMC Sierra 2500/3500 HD

Replaces degraded OEM ignition components to restore optimal spark energy, eliminate RFI interference, and cure misfires on the 6.6L L8T V8 engine.

The Stock Sierra HD Ignition Breakdown

Under heavy thermal loads from constant towing or prolonged idling, the factory ignition coils and spark plug wires on the T1XX Sierra HD inevitably break down. The stock coil's internal epoxy degrades over time, altering primary and secondary resistance values. This causes voltage leaks and weakened spark delivery. Inadequate spark results in poor combustion efficiency within the L8T cylinders, directly manifesting as sluggish throttle response, random misfires, check engine lights (CEL), engine hesitation, and noticeable drops in fuel economy.

The Engineering Solution

This comprehensive ignition overhaul kit is engineered to provide a 20% increase in spark energy over the OE factory components. The upgraded UF742 coils utilize premium high-conductivity copper windings encased in advanced, heat-resistant epoxy to prevent premature thermal breakdown. Capable of stepping up a standard 12V input to over 25,000V (maximum 26,000V with a precise 61:1 turns ratio), they deliver a robust and highly consistent spark. The included 41-114 iridium spark plugs feature an ultra-fine center electrode for superior ignitability, exceptional conductivity, and a high melting point to maximize complete combustion. Coupled with 8mm high-temperature silicone spark plug wires, protective heat shields, and wire separators, this system guarantees maximum voltage transfer to the chamber while completely eliminating RFI electronic interference.

Technical Specifications

Compatibility

• 2020 GMC Sierra 2500 HD 6.6L V8 Gas
• 2020 GMC Sierra 3500 HD 6.6L V8 Gas

The Heavy-Duty Caliber

Built for the rigorous demands of heavy towing and high-payload hauling, this ignition kit ensures reliable, misfire-free power delivery when pulling heavy loads up steep grades, preventing drivability complaints and pre-ignition.