K...after reading all the post........Im stuck between 22cc domes and 21cc....my bike has FMF pipes....+4 timing.....k&N...I plain on running 91 octane.....but...I will be buying a Coolhead in the next week or two.........so.....what would I buy?...22 or the 21 domes.....I'd like to have the same cc's as taking .010 off the stock head...and I am at sea level......any help would be COOL! :biggrin: