Hiya, just blown the head gasket trying to race a mondeo st24, i already have a ported and flowed head but never got it skimmed how much can i take off to improve performance and to leave room for another small skim in case needed, and to eventurly run kent cvh21k cvh22k or cvh32k or simular lift piper, also any bad side effects., its 1.6 CVH Xr2 engine with a lean burn head. Cheers BAZ