04 grand prix gtp, putting on my togs, tog dp, 3.5 pulley in a week, (car has a custom cai on it already)
i'm gonna go at least one heat range colder on plugs plus my msd wires, but i dont know if i should do 2 heat ranges?
what are they best one heat range colder plugs?
Best two heat ranges?
Think i need two heat ranges??? i'm stumped on this..