if you are na yet.........in my opinion just stay with the stock platinum plugs. You dont need copper for best performance until you have the SC and you dont need to drop heat ranges( i.e. autolite 104's) until you drop pulley sizes from the stock supercharger. So run the stock platinum's until you do your topswap and then you can change your plugs. If you go colder than you need to, you will lose MPG's big time.........the colder plugs are just used to combat knock retard with the superchargers. If you are getting headers, they come with their own down pipe, and if you dont want headers then use the Plog/ Downpipe setup...