new pipes will help with your power for sure. if you're wanting to ride in any sort of mud or water you best leave your airbox on. I always run 91 (the highest we can get here) in my shee, a lot of guys mix 50:1 just be sure your're using a good oil (AMS Oil, Klotz, etc). I personally mix 40:1 just because it works out perfect 1 bottle to 10 gallons...its more or less a personal preference thing though.
good luck with her though, 'shee's a good looking quad. O, and welcome to BHQ.