MerCruiser Thunderbolt V8 Spark Plug Wire Set by SierraFor 8 cylinder engines with Thunderbolt ignition systems.Features: Kit includes coil wire.; Kevlar core for maximum durability and long life.; Durable stainless steel wound conductor for maximum horsepower and engine performance.; Premium silicone jacketing and boots for the ultimate in high temperature protection.; Superior RFI suppression for the most sensitive electronic system.; Corrosion resistant stainless steel spark plug and distributor terminals for maximum conductivity.; Lead Lengths: (2) Spark 30"; (2) Spark 35"; (2) Spark 40"; (2) Spark 45"; (1) Coil 12"; Replaces: MerCruiser; 84-813720A4, 84-816761Q4, 84-816761K 4, 84-813720A3, 84-816761Q3, 84-816608Q61, 84-813720A, 84-816761Q4; Redline; RL8804, ; Mallory; 9-28001, 9-28002;