if your confident that you can keep the same shape and not go mad ie enlarging the ports then go for it. i would call it a tidy u rather than orting as imo porting involves gas flow testing and is a secialist arena. tidying up rough castings/matching is a cheap way to improve the ve to a degree. get it wrong though and your head will become an expensive paperweight. DONT polist the inlet side. instead use a stone burr with squirts of wd40 to give a nice finish. polished surfaces do nothing for gas flow on the inlet side. atmomising the charge is more important. i have always beleived olished surfaces helf reduce carbon on the exhaust side though aswell as aid ridding the spent gasses.