SPARKWHIZ UF413 Square Ignition Coils with 8mm 748UU Spark Plug Wires, Set of 8 — Direct-Fit, High-Discharge Energy

SPARKWHIZ UF413 square ignition coils paired with eight 8mm 748UU spark plug wires deliver a reliable, direct-fit replacement that boosts spark consistency across all eight cylinders.

Designed as a direct plug-and-play replacement for compatible Cadillac, Hummer, Chevrolet and GMC engines, this kit combines UF413 square-body coils and OE-style 8mm 748UU wires for improved discharge energy and dependable service life. The coils use high-quality copper windings and a protective polyester rubber wrap; the wires match standard OE specifications to maintain proper fit and resistance. Before buying, confirm compatibility using your vehicle’s year/make/model selector or compare to your original coil’s physical shape—round and square-bodied coils are not interchangeable.

How will these coils and wires affect everyday driving?

Upgrading to UF413 square coils with matched spark plug wires can produce a steadier, more consistent spark under normal and demanding driving conditions. That stability helps the ignition system run more evenly, which can improve throttle response and reduce misfires when the original coils begin to age.

• Higher discharge energy than many stock coils for consistent ignition
• OE-style 8mm wires preserve factory routing and connector fit
• Durable materials resist heat and vibration for daily reliability

Will these parts fit my vehicle and how do I check?

Fitment depends on the coil body style and your vehicle’s original part numbers. Use the year/make/model drop-down on the product page or compare your original coil to confirm you need the square UF413 (D510C) style rather than the round UF414/D514A style.

• Cross-referenced OEM numbers include C1511, UF413, D510C and others
• Intended for select Cadillac, Hummer, Chevrolet and GMC applications
• Visual check: match square-bodied coil shape and connector location

What should I know about installation and long-term care?

Installation is straightforward with basic hand tools, but a few precautions help avoid damage. Applying silicone spray on rubber components before assembly eases installation and prevents cracking; use original-style tools where possible to ensure proper seating.

• Plug-and-play design for direct replacement on compatible engines
• Spray silicone on rubber parts to prevent cracking during install
• Follow torque specs and routing to avoid wire strain and interference

What materials and construction give these coils durability?

SPARKWHIZ engineered the UF413 coils with high-grade copper windings and a protective polyester rubber wrap to withstand heat and vibration. The matched 8mm 748UU wires use standard OE insulation and terminals to maintain consistent electrical characteristics over time.

• German copper coil windings for robust electrical performance
• Polyester rubber outer wrap for resistance to heat and mechanical wear
• Standard 8mm 748UU wires for reliable continuity and fit

Who is this for: This set is aimed at car owners and mechanics seeking a reliable full-bank replacement for eight-cylinder ignition systems where the square UF413/D510C coil is specified. It suits DIY enthusiasts doing scheduled maintenance, professional shops replacing worn coils, and performance-minded drivers who want stronger, more consistent ignition than aging factory units provide. Always verify fitment and coil body style before purchase to ensure correct installation.