Thanks for all the input! I can tell you I put splitfires in my last Dodge Caravan- and it totally messed up my engine. It would lose power while driving and kick. I had such a hard time getting to the rear plugs ( transverse engine) that I had the dealer replace the plugs and take the splitfires out after a week. I will never again use modified plugs in my vehicles.

FYI I just purchased NGK's from a local auto parts store for $6.19 each and am going to put them in this weekend.