I've got an 03 with 20,000 miles on her. Mods are: #2 upper, Modded stock box, FTVB. I will be getting the SCT Programmer and a dyno tune in a few weeks. I am also strongly considering headers. At what point should i get new plugs? THe ones in there now are the stockers, and as I said have 20,000 on them. Considering my mods, is it time for new ones, and whcih ones should i get?

 

I also have an 03'. I run denso IT 20's with a 4lber.