New intake manifold worth it?

I do drive it hard when I do, and it loves to rev so I dont mind bringing the RPMs up, but yes its not all the time so maybe ill leave the manifold where it is.

I have been wondering about the carb as well, so a 750 would be a better option? Oddly enough I tested it with an 850 carb and the throttle response was night and day, didnt get much of a driving test because it was way too lean for some reason.