Ignition Coil + Spark Plugs for GMC C2500 C3500 K2500 K3500 (1996-2000) 5.7L 7.4L

Direct Replacement Ignition Coil & Spark Plug Tune-Up Kit for 1996-2000 GMC C/K Trucks (GMT400)

What it Does: The ignition coil and spark plug kit replaces aged factory ignition hardware on 1996-2000 GMC C/K Trucks to eliminate secondary ignition breakdown, misfires, and unburnt fuel cycles under heavy payload demands.

The Stock GMC C/K Trucks Thermal Breakdown and Voltage Leakage

The factory ignition setup on GMT400 platform trucks routinely encounters dialectric failure at the external ignition coil and thermal erosion across the spark plug electrode gaps. Located within an engine bay prone to severe thermal soak, the stock epoxy potting within the factory coil degrades over time. This leads to internal primary-to-secondary winding shorts, insulation breakdown, and micro-arcing. Simultaneously, extended service intervals erode the standard copper or nickel spark plug gaps on the Vortec 5700 L31 and Vortec 7400 L29 powerplants. The widening gap increases primary coil dwell strain and demands higher secondary strike voltage, culminating in high-load hesitation, rough idle, and DTC P0300 misfire codes during high-temperature towing cycles.

The Engineering Solution

This comprehensive tune-up assembly delivers matched impedance and high-voltage dielectric isolation tailored to factory dwell tables. The replacement ignition coil features high-grade magnetic steel core laminations wound with high-purity copper wire, encased in high-dielectric epoxy to resist high-heat vibration and moisture penetration. The kit matches 8 matched-gap spark plugs engineered with high-alumina ceramic insulators and erosion-resistant electrode metallurgy. This direct-replacement kit replaces OE numbers like 10489421 and D577, restoring arc energy, maintaining stable spark duration across the entire RPM range, and preventing unburnt hydrocarbons from fouling downstream catalytic converters.

Technical Specifications

Compatibility

• 1996-2000 GMC C2500 5.7L V8
• 1996-2000 GMC C3500 5.7L V8
• 1996-2000 GMC C3500 7.4L V8
• 1996-2000 GMC K2500 5.7L V8
• 1996-2000 GMC K2500 7.4L V8
• 1996-2000 GMC K3500 5.7L V8
• 1996-2000 GMC K3500 7.4L V8

Frequently Asked Questions

Does this fit the GMT400 C/K Trucks?

Yes, this is a direct fit for the 1996-2000 GMC C/K Trucks equipped with the Vortec L31 (5.7L) or Vortec L29 (7.4L) engines.

Are spark plug wires included in this service pack?

No, this package includes only the single high-voltage external ignition coil and 8 matching spark plugs; secondary HT leads are sold separately.

The Heavy-Duty GMC Standard

Engineered to handle sustained commercial hauling and demanding tongue weights, this ignition refresh restores the raw low-end torque curves and combustion consistency necessary to keep heavy-duty GMT400 chassis working reliably under full gross vehicle weight ratings.