Hey guys, JC and Kmutt especially, HellFire's the man on these matters. You might want to look at this thread I started when I made the changes
http://www.r3owners.net/bearclaw-corner/8688-site-rocks.html?highlight=site+rocks. I was running lean and to fix that I went with Dobeck instead of a PCIII when I added the filters. The Dobeck is arguably an easier option although not everyone agrees it's better. It suits me because I can fiddle with it anywhere, any time - a bit like old fashion carby tuning. The bike really howls when I want it to, is super smooth and not too bad on fuel.