MAS Ignition Coil and Spark Plug Kit for Ford 4.6L/5.4L V8 — 8 DG521 Coils with Brown Boots + Motorcraft SP-509 Plugs

MAS complete ignition kit: eight DG521 coils with brown boots plus Motorcraft SP-509 spark plugs for Ford 4.6L and 5.4L V8 engines.

If your Ford truck or SUV is showing misfires, rough idle, or diminished throttle response, replacing the entire ignition coil and plug set can restore consistent spark delivery across all eight cylinders. This MAS kit bundles eight coil-on-plug units with brown DG521 boots together with Motorcraft SP-509 spark plugs so you can do a full ignition service in one go. The parts are designed to fit many Ford vehicles that use the 4.6L or 5.4L V8 engines and include common OE cross-reference numbers for easier verification.

How do I confirm these coils match my vehicle?

Start by checking the color of your existing coil boots: this kit is for the brown-boot DG521 style. VIN lookup, owner’s manual parts lists, or comparing part numbers on the old coils (C1659, DG521, SP509 cross-references) will verify fitment. If your original coils have black boots, this kit will not be correct.

• Confirm coil boot color — brown required for this kit
• Compare OEM part numbers: C1659, DG521, FD-509, SP509
• Typical fitment: 2008–2014 Ford models using 4.6L or 5.4L V8 engines

What vehicles and engines are compatible with this MAS set?

The kit is engineered for Ford 4.6L and 5.4L V8 applications found in popular trucks and SUVs. It covers model years and vehicles commonly listed by owners and parts suppliers, but always verify fit before ordering. This ensures the ignition geometry and plug reach match your engine’s specifications.

• Ford Expedition (2009–2014)
• Ford F-150, F-250, F-350, F-450, F-550 (2008–2010 ranges as listed)
• Lincoln Navigator, Lincoln Mark LT, Ford Explorer, Mercury Mountaineer, Mustang (specified years)

What are the performance and durability features of the coils and plugs?

MAS coils use heat-resistant compounds in the coil-on-plug boot to better withstand under-hood temperatures and repeated thermal cycles. The coils are built as direct replacements with high-energy output characteristics to match OE ignition timing and spark demand. Motorcraft SP-509 plugs are included to provide the correct electrode design and reach for these engines.

• High-heat-resistant boot compound for extended durability
• High-energy coil design for consistent spark delivery
• Includes Motorcraft SP-509 plugs for proper gap and fit

How easy is installation and what does the kit include?

This set is intended as a direct-fit replacement so that most mechanically competent DIYers or technicians can swap out coils and plugs without modifications. The package contains all eight coils with brown DG521 boots and eight Motorcraft SP-509 spark plugs, giving you a complete ignition refresh in one purchase. Basic hand tools and a torque wrench are recommended for correct plug installation.

• Complete set: 8 coils + 8 Motorcraft SP-509 spark plugs
• Direct replacement fit for compatible models, no modifications
• One-year limited coverage for parts assurance

Who this kit is for: drivers and independent mechanics who need a full ignition system refresh on Ford 4.6L or 5.4L V8 engines and who confirm their vehicle uses the brown-boot DG521 coil style. It’s especially useful when multiple cylinders are affected or when you prefer replacing all coils and plugs at once to avoid repeated labor. If your vehicle uses black-boot coils, choose the appropriate alternative part instead.