know some quick tt xt sr 500's and in sidecars all use VM36 IWT Ian Williams will do you a treat on a new one.
big bore kit say 560cc use VM38 round slide
ask for carby to suit and start rich, these guys have all the poop, may I suggest the SUDCO 5th editon Mikuni tuneing manual its great value about $25 + post has everything in there (bible)