400ex motor questions!!!!

[jk250r]

i have an almost all stock 400ex. i am going to completely strip down and then make it into an awesome xc race ready 4??ex??? My biggest concern is what to do to the motor??? Should i make it a 416,426,440,etc???? Also who should i get to do the motor work??? Please give me any advice as to what size motor to go with and also what all does this work involve (port,polish,piston,cam,etc.)?? PLEASE HELP ME!!!!!

[Gillbilly]

I was just going to post this same question.I think Im goingwith a426 for reliability issues.I was wondering about peoples choices on chassie mods and other lesser mods.Any input would help.