The Japanese were not known for making "universal fit" on things like frames. Even if you found a frame that fits the engine, you will run into other problems in getting the front end to swap over and then fitting the rear wheel and getting the rear wheel sprocket to line up with the engine sprocket. Why not consider hopping up the KZ440 engine instead?
You can likely enlarge the engine displacement, install hotter cams and add a header for more HP.
You can likely enlarge the engine displacement, install hotter cams and add a header for more HP.
