It would be interesting if there was a way to have a hydrolic valve adjustment and still keep the OHCs.
larger cc displacment the closer to 1000 the better. 6 speed definately. no more air boxes pod style air filters in perferated metal covers. Slip in adjustable baffles. some type of built in air fuel mixture adjuster that would allow you to dial up the fuel.

I have no faith in human perfectability. I think that human exertion will have no appreciable effect upon humanity. Man is now only more active - not more happy - nor more wise, than he was 6000 years ago. Edgar Allan Poe