well the only thing i would be worried about is your crank and the clutch. You should split the cases and get the crank welded, and while you got it apart you should call Jeff at FAST racing and order is clutch kit your stock one won't hold up long. Um you ought to mod your shift star for ease of shifting and another thing you will need is a longer swingarm for sure, unless you reallllly like riding wheelies.
My bike's lower end isn't nothing much over stock either, Its got a 4mill stoker crank trued and welded, EBC kevlar clutch(I bought it before I knew about Jeff), modded shift star. timing advanced 7 degrees. then up top its just 68.5mm bore with 58mm stroke to make it a 427cc. with the ports just matched to the stroke not really drag ported. its got 12cc domes with a squish clearance of 40 thousands and it's on alcohol. and i run rocket pipes with a +6 swingarm and 35mm airstrikers. I think thats pretty much it.