SYKRSS Ignition Coil & Iridium Spark Plug Kit for Ford 5.4L/4.6L V8 — 8 Coils + 8 Plugs, OEM Fit & Durable Upgrades

SYKRSS Ignition Coils Pack with 8 DG508-style coils and 8 SP479 iridium spark plugs is a complete direct-replacement tune-up to cure misfires, rough idle, and restore lost power on 5.4L/4.6L Ford modular V8 engines.

This all-in-one kit replaces worn coils and worn spark plugs on Ford F-150, Mustang, Expedition, E-Series, Crown Victoria, Lincoln Town Car, Mercury models, and select commercial vehicles using the 5.4L or 4.6L V8. Each coil is built to OEM fitment specifications while using upgraded internal components for improved durability; the included iridium plugs are pre-gapped to factory spec so you can install and go. The package targets owners seeing misfires, rough idle, check-engine lights, or a drop in throttle response—especially vehicles past 60,000 miles on the original ignition parts.

How will these coils and plugs stop my misfires?

The SYKRSS coils deliver strong, consistent secondary voltage while the iridium plugs produce a focused, stable spark. Together they address common ignition weaknesses—cracked boots, degraded windings, and eroding plug electrodes—that cause intermittent or persistent misfires.

• Full-set replacement: 8 coils plus 8 iridium plugs to eliminate weak links across all cylinders.
• Upgraded internals: German enameled copper windings and Japanese epoxy potting resist vibration and heat.
• Plugs pre-gapped to 0.054" for correct spark gap out of the box.

Are these a straightforward bolt-in for my Ford 5.4L/4.6L V8?

Yes—these are engineered as direct-fit replacements matching OEM dimensions and electrical connectors. No cutting, splicing or adapter harnesses are required when you replace the coils and plugs on compatible Ford modular V8 heads.

• Replaces OE numbers including DG508, DG481, DG491 and 1L2Z12029AA among others.
• Installation note: torque spark plugs to exactly 25–30 N·m (22 ft-lbs) to avoid stripping shallow aluminum threads.
• Plugs and coils are keyed for factory harnesses—fits OEM mounting points.

How durable are these parts under real-world conditions?

SYKRSS designed the coils to endure under-hood extremes that kill cheaper units. Components and materials are selected to survive wide temperature swings, high vibration, and prolonged duty cycles typical for trucks and performance cars.

• Silicone boots rated for 105°C continuous, peak-tested to 125°C to resist cracking and carbon tracking.
• Coils potted in Japanese epoxy to block moisture ingress and protect windings.
• Environmental testing from -40°C to high-heat cycles mirrors cold starts and hot towing conditions.

Who is this for? This kit is aimed at DIY mechanics, fleet managers, and performance-minded owners who drive Ford 5.4L or 4.6L modular V8 vehicles and want a reliable, OEM-fit ignition refresh. It’s especially useful for trucks and SUVs with higher mileage on original ignition parts, anyone troubleshooting cylinder misfires or intermittent engine lights, and owners who prefer pre-gapped iridium plugs and robust coils to reduce repeat visits to the shop. SYKRSS also supports buyers with a 1‑Year Replacement Promise and a fitment check—send your VIN or Year/Make/Model before installation for a quick verification.