I built a lot of SBCs back in the day. It was not too hard to run with the big block muscle cars, if it was in a light body, and had some simple mods. What is the reason you are thinking of the OHC design? It would not yield any appricable RPM gain... and would probably be a lot more expense than to adding a turbo or supercharger. The only thing that seems a real gain from my experience is the visual impact.
If you are looking for something more visually stimulating... maybe a set of custom milled valve covers with some creative design work... and maybe an unusual intake of some sort.
I've seen some locals doing experimentation with designing electronic injection setups. and getting a visual boost in the process. Unless you could find an aftermarket setup, you might search for local talent that is sophisticated enough to build something with computer control.