Moroso 73663 Ultra 40 Blue Spark Plug Wire Set 8.65mm 90-Degree Non-HEI

The Moroso 73663 Ultra 40 is a custom-fit, high-performance spark plug wire set engineered for serious racing and street performance applications. Built to the same specification as wires used across motorsports from dual-magneto Top Fuel dragsters to the NASCAR Cup Series, these wires deliver maximum spark energy with outstanding RFI/EMI suppression.

At the heart of the Ultra 40 design is a spiral-wound nickel/copper alloy conductor wrapped at the optimum ratio to deliver the highest level of spark energy transfer while minimizing electromagnetic and radio frequency interference. The ferrite-impregnated, conductive polymer-coated core works in tandem with a Kevlar® center core — four times stronger than standard aramid fiber cores — to provide exceptional dielectric strength and wire durability.

Key Features:

• 8.65mm diameter wire with a class-leading 40 ohms of resistance per foot for optimal spark energy delivery
• Kevlar® center core — 4x stronger than standard aramid fiber cores for superior dielectric strength
• Nickel/copper alloy spiral-wound conductor for maximum spark energy transfer and EMI/RFI suppression
• Ferrite-impregnated core with conductive polymer coating for enhanced interference resistance
• Extra-thick EPDM layer provides greater dielectric strength and insulation
• Closely woven fiberglass, silicone-impregnated insulation adds up to 8,000 extra volts of protection
• High-temperature silicone boots rated to withstand heat up to 600°F
• Locking stainless steel terminals with fold-over crimping for a secure, corrosion-resistant connection
• Outer silicone jacket protects against exhaust header heat, chafing, and contaminants
• Blue wire finish with 90-degree plug boots, custom-fit for non-HEI distributor applications

The Moroso Ultra 40 wire set is the benchmark in high-performance ignition wiring, trusted at every level of motorsport competition. Its multi-layer construction extends wire service life while ensuring consistent, reliable ignition performance under demanding conditions.