The head squish/modification and explanation is listed in the Tech Articles.
http://www.gasgasrider.org/html/measuring_squish.html
2K2 ignition will help (it's just marginally lighter than the 2K3 but the 2K3 carries it's weight different) , remove reed spacer if you have one, different pipes you can try, thinner base gasket, carb can be bored out to 39mm to increase mid to top end.
Skidad