Manifold porting definitely works. Provided you have heads, carb, cam etc. to match my belief is the manifold porting is part of the package that allows the engine to run up to the RPM limit and not run out of steam.
Pulling hard and making HP right to the limit is something I try for.
You can do a decent job of port matching and working on the plenum area at home with a hand die grinder.
I have one with an extended long slim shaft that allows you to get a fair way up the manifold runners.
Try to straighten the port entry and not make a "bell mouth" shape.
There is plenty of info out there about what not to do.