what do i need 2 do 2 get 60-70hp out of my banshee ?

pipes, carb, boost bottle, filter! It will HALL A*S!

Dont get a boost bottle, their junk. Get a pair of CPI inframe drag pipes. They sound mean as hell and are sick pipes. Get 2 new carbs. I believe the stocks are 26, so go to like a 30 or a 35 maybe if your planning on motor work. Get a foam uni filter, and depending on your riding conditions it may be possible to run no air box lid. If you want to go any further get motor work done, porting, mill the head, re-sleeve, bore, etc. By this time your going to need an extended swinger to control the damn thing. If you want more power look into a stroker crank.