Originally Posted by bmwrench
On the other hand, you could really cheat, taking the motor out to 750cc. As long as you don't look significantly faster than the other bikes, or win too often, no one should ask for a tear down
I need to keep it legal, 500cc max. With a R50/5 bottom end, pistons, and jugs, can you use R60/5/6 heads ? Would the larger valves help or hinder the performance ? Or would it be better off sticking with the R50/5 heads and just do a good port job ?