Well, IMHO with this question and NO other info. about your RC51... (is it stock? What mods. do you have done, Full Headers Exhaust system, or Slip-Ons, Thorsten or Turn-One AirBoX?) it really is up to you... Are you running her on the Street, Track day machine or both, RACE only?
IF You are wanting High HP#s, Look else where, meaning another MC. IF You want a Killer MC in the corners and good all around handlin' FUN machine... look into doing forks, shock, Rims, and AirBox!
Now, again My:twocents IF you are at point working on the "heads" anyway... then sure why not... but "I" would Not just go and dive in, just to do this. As a matter of fact.. I have above mentioned mods. ++ and I have NOT messed with the heads.
I Hope this Helps,..?