hi mate ,im doing similar 2008 kxf250 frame ,jan de groot kx250 grand prix engine if i remember correctly sprocket side spacer 9mm kickstart side 8mm i used a 17mm drill on the lathe and turned them down to 28mm used the old chain buffer on the swing arm for reference but will ping a lazer down the centre line before i weld it up ,i will check tommorow on the spacers with a vernier and let you know ! not sure what im going to do about the LH rad mount very tight to say the least on the rad , prob cut off and reweld on . ground the old tube out of the cast part of the frame still had to file down after the die grinder , jerrys rails fit atreat just got to trim down for lenth. ta jerry