Care full on the "get as much as I can" exhaust flow. You can get to much. Ideally you want 75% of the intake flow on the exhaust side, so work on both ports if you do anything. As for porting, remove all sharp edges and rough casting and try to maintain a even port size from the valve to the end of the port. A long, cool torch flame pointed down the port will show you where the air flow likes to go. If it jumps off the wall trying to make a corner, work on the corner. Same idea as water flowing off a car, it likes to follow a certain curve, any more and it splashes off.
On the Inliners.org site, they cut one of those heads apart and showed the internals and how to port one, do a search and read up on it.
Joe
