• For Mercruiser 7.4 liter 454 cu. in. Pre Vortec engines with Thunderbolt ignition systems
• Mercruiser tune-up kit includes everything in one convenient package
• Includes 8 NGK BR6FS Pre Vortec spark plugs, plug wires, distributor cap, rotor, 18-7844 fuel filter, 18-7824 oil filter and 8 oz. StarTron gasoline additive
• Due to the gasoline additive this kit ships GROUND ONLY!!!Cannot ship NEXT DAY AIR, 2ND DAY AIR or 3DAY SELECT!!!