450 is more than enough for any all motor set up meant to be on the street... 310cc is what they usually reccommend, i've also heard of 270cc for a bare set up and 340 for a wild set up...
you can choose to use those 450cc and use them at half cycle or whatever... if you dont want them let me know who is selling them so i can buy them

cause im lookin for a set of 340cc or more