Probably cheaper in the long run to just shop for a 600 (or bigger). There are a bunch of them out there, and it would save you a lot of headache and wrench time for the incremental gains (and likely geometry issues you would encounter.) Yes, the 500 may well be a great handling bike, but it's designed that way with that motor. I've seen too many nice bikes ruined (IMHO) by stretching this or stuffing geometrically wrong engines (or mods thereto) into them. If you like your 500 (that's cool) keep it, but if you want more umph, get a bigger bike. I know this isn't what you may want to hear, but guys with (no offense) smaller bikes or older bikes (like MINE!) complain of this quite a bit; it's called the "if only" syndrome.