So I'll assume since I only got one reply(from afm), that everyone here uses the NovaRossi plugs in there Sirio???
Well, thats fine, as long as they're good plugs, work well, and have a reasonably good life span. The info on these plugs says that if I'm using over 25% nitro, to stick with the C7S or C8S. Since I'll be using 30%, I guess I'll be going with those.