Porting KZ heads

I recently discovered Schumann Motor Works. out of Milwaukie OR. He specializes in vintage Japanese cylinder heads. He is doing a full custom valve train for my kz750 including a port and polish. Very reasonable prices.

Might as well get started on this one.
Steve

Kind of on topic, I am working on a new engine for my car and thought I would try porting and gasket matching on it. Its a Suzuki G13BB which is pretty common so I can get replacement manifolds cheaply (head as well if need be) if I ruin it, but is this something I should still avoid? I am trying to get more performance out of it, but not really a "track machine/drag car".

Some of you have said it can do more harm than good. Is that worse than stock/original or just not really any better than it was?

EDIT:
I should add, I'm trying to use this build as a learning experience as much as I can.

There is a video about matching manifolds to the gaskets and heads. Good info. He also says polishing the intakes can be a mistake. They need to be a little rough for atomization. In two strokes it's a different matter.
Steve