Thanks for info Tommy.
No any mods required at all on P/S set. Any modding might kill performance. Power comming not from cuts on sleeve and timing altering ( BTW timing setting is standart-4.5 mm exhaust height), power comming from materials set up and piston material properties and initial angles on ports. Higher exhaust timing will required different pipe settings and it will be like start from the beggining-look for better pipe lenght ( everybody already got expirience on pipes over the years so will need to forget about it).