I will disagree with what BSHEE400 about bigger carbs. My 4mil ran like a champ on stockers. I've been told time and time again that smaller carbs will net better low end.
My vote is a port job(depends who your nuts swing from, mines flotek of course), vf3 reeds, milled head(if you dont want to buy a cooling head), a good driver and TRACTION.
Anyways, read very close what Burt Reynolds said. You GOTTA put that power to the ground.
Check this video outof my buddy riding my sheet. It's his first time racing it. My bike is pushing way more power than the others. However, for the difference in power is has, it sure isnt beating them by much. And if it didnt have an override, subtract about 3-4 lengths or more off each race. Yes it makes that much of a difference. Now if you look at the end of the video, a nice stretched yfz450 that is set up eats my bike alive again and again. Set for the win. Moral is dont port the bike etc and go out there thinking you will win. You might have the power but you might not have the skill or traction to do it. I've lost more than i won for sure on my banshee.