FMX---Open the ports right out to the gaskets on both the intake and the exhaust. Polish the exhaust ports---leave the intake ports unpolished. The conventional wisdom used to be that the air/gas mixture should be somewhat turbulent as it flows into the cylinder for better dispersion of the gasoline vapour into the air for an even burn with no hot spots, and this is best accomplished by flow over an unpolished surface. Although this porting and polishing used to be quite effective on the old flathead engines that didn't breath all that good anyways, I doubt that you will see much difference on an overhead valve street motor. Maybe if you have a drag car where you're trying to shave tenths of a second off your E.T., but for a steet motor ?????