yes i sort of understand that bit.But unfortunately i didnt have the work done so im not really sure what the spec is.I was told the cases were flowed and matched to ported cylinders and power valves, straight plug head conversion and a kiss delimiter.I was under the impression that apex were the main boys for tuning nsr's from the previous owner however ive since found out they are not trading at the moment and thought maybe someone here may have had apex work on their bike and just have a rough idea.Just need something to go off as i would not like it to blow due to my poor maintainance, thanks