A special thread and shell coating ensures quick and easy removal from aluminum heads and resists corrosion.

• Gold palladium insert extends life and improves resistance to corrosion
• Tapered tip provides better spark exposure to air/fuel mixture and allows the mixture to flow more easily through gap area for maximum combustibility
• Fouling resistance is improved with smaller diameter center electrode wire and insulator tip
• Copper-cored ground electrode runs cooler for extended life
• Anti-seize coating on threads
• Anti-seize coating on threads

Fits late '78-'84 Shovelhead and '84-'99 Evolution® 1340-equipped models or use in place of Nos. 5R6A and 5RL.