United Marine 103 Thunderbolt Small Block Spark Plug Wire Set – Mercruiser 305/350

Complete 8-wire set plus ignition coil wire for Mercruiser small block V8 engines with Thunderbolt ignition systems. Blue 8 mm SSC 100% silicone wires with 90° boots on both ends for clean routing and secure fit.

• 8 mm blue SSC 100% silicone jacket – 500 °F heat rating, high tear strength
• Ultra-low 270-ohm/ft carbon-latex core for maximum spark energy
• Superior EMI/RFI suppression prevents tach bounce, radio static, and ECU interference
• Heavy-duty molded boots maintain dielectric strength in wet/salt environments
• Stainless steel + brass snap-lock terminals resist corrosion and arcing

Fits:

• Mercruiser 305 cu. in. (5.0L) and 350 cu. in. (5.7L) V8 engines (1983–1998) with Thunderbolt IV/V ignition

Replaces:

• Mercury 84-816761Q4, 84-43376A4, 84-816761T4, 84-813720A4, 84-816761A4

Manufacturer Part No.: 103 Brand: United Marine Availability: In Stock – Ships Free (when order qualifies) Hazmat: No