everything that can be done since it can't be bored. if I was still in OK, it would get 200hp, it's only getting 180hp here in NV. less humidity, less oxygen, higher altitude, etc is why it's not getting all the power it would be otherwise.
mods:
head flowed/ported, degreed cams, swapped exhaust cam for an '08, aftermarket clutch basket, did away with all the emissions/crap, boz brothers slash-cut exhaust, 14.7-1, hid headlights, 520 chain conversion, every little thing that wasn't needed was taken off as well. so, pretty much everything and anything that can be done to a zx10 motor since the 10's can't be bored