Thunderbolt Tune Up Kit MerCruiser 4.3L Vortec | MMD M43TBOLTGEN MerCruiser 4.3L Vortec Thunderbolt Tune Up Kit | MMD M43TBOLTGEN Comprehensive kit includes the items needed to tune-up Gen+ Vortec Mercruiser 4.3 liter engines with Thunderbolt ignition system. Normal annual maintenance items including distributor cap, rotor, spark plugs, spark plug wires, oil filter, fuel filter and fuel treatment For Mercruiser Vortec Gen+ 4.3 liter 262 cu. in. GM models using Thunderbolt ignition and NGK BPR6EFS projected tip spark plugs Packaged conveniently in one easy part number to order Just add the recommended engine oil