like i stated and gscx , ive heard it done, but i dont think its worth it, when ya can just pick up a good rolling yz frame for cheap and feel some serious power. trying to slam that engine in a blaster frame youll have a serious job ahead of you, and getting a colling system mounted is prolly gonna make you pull allot of your hair out. not to mention all the other problems your gonna run into (frame reinforcment, motor mounts, gearing etc..) and as far as a 250r motor goes, why would you??? id rather have a built blaster motor any day of the week...
about the yz gscx...pm me, we can chat