Yeah, iridium plugs last a while but they make a hot spark, and once you start modding, you will want colder to keep it from chipping a piston.

http://www.grandprixforums.net/threa...00-Powered-Car!!

There's all the info you will need for the beginning of your modding, and your engine will stay happy for many years.

If you decide to get colder plugs, most places will take spark plugs back as long as they haven't been opened.