Port you're head? You mean the complex task of modifying intake and exhaust ports and valves to improve flow into the combustion chamber that is part science, part art and requires a very good knowledge of the topic and experience to do well? The answer to youre question is you dont do this in youre driveway, you have to find a good experienced head porter and have them do it for you.
there's guys out there that talk a big game, and have been doing it for 20 years and still dont know what the hell there doing so its important to take your time and find the best, and to spend the $ on it. Its deffinitly not a do it your selfer.