RE: Altering port timing/effect on power question
A great exhaust system will have way more affect on performance than anything you can do to the port.
The manufacturers would just change the ports if it was just that simple.
I'd go for bigger displacement.
Alternately, [link=http://jettengineering.com/]http://jettengineering.com/[/link]has this figured out and maxed out but it comes with a pricetag.