Champs are a crap plug. Get NGK's and platinum is just fine....they use a copper core just like the cheapies but the tip lasts longer. Even if you stick to the 30k interval it's still worth the extra cost because the plats will hold gap the whole time. Cheap champs will lose gap in half that. There's no need to go colder for just a tune and/or full bolt-ons.

 

I see by your sig that you are running a stock truck on an econo tune. In you'r case, no, colder plugs wont help, but with a performance tune and higher octane fuel cooler plugs promote a cleaner, more complete burn. With the addition of timing from performance tunes, cooler plugs are bennificial, not necessary, but they help prevent pinging.