I know you're supposed to do them all when you do plugs, but i'm just wondering because the original plugs,wires, cap, rotor lasted 100k... I'm just changing the plugs because I recently did the seafoam treatment. So if the originals lasted 100k, then why replace at 130k? But I probably will. So... Which plugs, cap, rotor, wires, etc? I know Delco makes a couple different types of plugs, as does Bosch wires.