i dont get valve bounce at 5000rpm just dosnt make power above it.

i thought that it valve bounces at 6200rpm which limits it's ability to rev further. dont think it the carby stopping it from reving over 6200 RPM could be the cam?

so with stock cam and just changing springs it should rev a bit more but will it make more power at the higher rpm or do you require a different cam and ported head?

Thanks!