i used first over size xl125 aftermarket piston and ring sets,so the bore was done and honed to those pistons,the wrist pin(gudgeon pin)and deck hieght is the same,,i did however have the head combustion chambers relieved to clear the piston crowns and to also lower the static compression ratio,david silvers have a good "search by part numbers "web page,fiddle about in there and im sure youll find an answer.