Quoting Terry Posten:
NGK copper resistor.
7s for stock, 6s for boost over 20psi.
***EDIT***
I mis-read the post, my reply is for plugs, not wires. Sorry about that.
I found the hotter plugs were more of an issue at higher boosts, and stock calls for 6's. Going colder at higher power levels seems to work best, though I'd recommend the non projected plugs, they always worked better for me. BR7ES all the way. /ubbthreads/images/graemlins/laugh.gif
I've had the regular "cheap" ngk's and the expensive magnecores. The only thing I can tell you about them is that they're thicker and cost more. I never saw a difference. /ubbthreads/images/graemlins/dunno.gif