Join supermotojunkie.com and read the threads about 500 smokers on the street. I have read a few build threads where they have done modifications to get longer engine life out of them. There was actually a for sale thread for a kx500 sumo not too long ago. check it out it might give you some ideas for mods. I have a cr500af myself and these things are ridiculous in the woods. I cant even imagine how fun they would be on the street. I have a wr450f sumo in Pittsburgh so when you get it built we should ride. Do you still live close by?