Powervalve cheetah!!!!! I absolutely love mine and will probably never get away from them again!! You may lose a little on top, but the mid and bottom end are amazing!! By this statement, I am in no way trashing the topend of the cheetah, mine pulls harder on top than anything I have ever rode. But, in talking to my builder, he said that he can get more topend out of a cub vs a cheetah!! It is kinda hard to believe you are even on a banshee, the first time you ride with the cheetah cylinders! Just my .02!! My riding buddy has a 421 cub and the first time he rode my 421 Cheetah, I almost had to pry his lil smiling ass off of it!! Do some research and check into a Cheetah!!
Z