Denso 671-8074 Spark Plug Wire Set

Denso 8mm Spark Plug Wire Set 671-8074

Denso 671-8074 is a First Time Fit spark plug wire set built to match the form, fit, color, and performance of the original factory wire set. It is an OE-style ignition wire replacement for classic Ford, Mercury, and Lincoln applications, including Ford F-150, Mustang, Thunderbird, and Mercury Grand Marquis models.

Key Features

• 8mm insulation outside diameter for OE-style ignition wire routing and fitment
• Silicone spark plug boot material for heat resistance and durability
• 115-degree spark plug end boot angle for tight engine bay routing
• Female spark plug end terminal type and female distributor/coil end terminal type
• Built to meet or exceed OE/OES standards for construction and performance
• Direct replacement for classic Ford, Mercury, and Lincoln ignition wire applications

Product Details

This Denso 8mm spark plug wire set is engineered for vehicles that require a factory-style ignition lead with the correct boot angle, terminal style, and insulation diameter. The First Time Fit line is Denso’s OE replacement product line, focused on matching original equipment specifications for reliable ignition performance and proper routing. Part number 671-8074 is a strong match for owners servicing older Ford F-100, F-150, Bronco, LTD, Mustang, Thunderbird, and related Mercury and Lincoln models.

This part cross-references NAPA Mileage Plus 6718074 for the same application.

Common Problems It Can Help Address

• Misfires caused by worn or heat-damaged ignition wires
• Hard starting from weak spark delivery
• Rough idle related to deteriorated wire insulation
• Voltage leakage from cracked or aged plug boots
• Poor engine performance on classic Ford, Mercury, and Lincoln ignition systems

Installation Notes and Tips

Verify engine application, routing, and terminal style before installation. This wire set uses 8mm insulation and female terminals, so matching the original configuration is important for proper fit. Inspect spark plugs, distributor cap, and coil connections at the same time to avoid repeat ignition issues. For fitment examples, this part fits 1978-1983 Ford Mustang, N/A; fits 1979-1983 Mercury Grand Marquis, N/A; and fits 1982-1983 Lincoln Town Car, N/A.

Quality Assurance

Denso’s First Time Fit line is built to OE/OES standards for form and performance, using construction that meets or exceeds original equipment requirements. Part number 671-8074 is intended as a direct-fit ignition wire replacement for the listed classic vehicle applications.