I think it all depends on how and where you spend your time. If you are looking at that XE274 cam, the total lift is under .500". So in my opinion there is not going to be much gained working on the runner of the intake port. Just smooth it out a bit, and make sure the port opening in the head matchs the port on the intake manifold. There is no need to open both up to match the intake gasket. Spend most of your time cleaning up the bowls and the short side radius (the transition from the bowl to the port runner). Don't go wild trying to hog it out, just remove any sharp edges and smooth all the transitions. I have heard the exhaust side is more restrictive, so that is probably where you'll get the biggest gains. I would guess you could pick up 10-15 hp with a few hours of work.
