Knowing exactly what to do to the ports for a particular engine package is ONE OF THE COMPONENTS of an engine package that is needed to make an engine run really well.
I have seen port jobs that looks like they were done with a chain saw or a motorized post hole digger that ran very well because the guy that did the porting had done the necessary testing and knew what to do to the ports but was in a big hurry.
I have also seen more port jobs than I can count, that were works of art that would not make power or the power was not usable. A lot of time was spent on these beautiful port jobs using the right tools, by highly skilled hands but did not know what porting dimensions to use on that particular model and application.