Head Porting basics

ou812 said
The pushrod pinch is the SMALLEST point in the entire intake tract. Forget the flow bench...making the pushrod pinch large will help HP at all levels in this case. Just don't break through if you can help it.
Also if you open up the SMALLEST point (pushrod pinch) you'll help airflow down the port and that will help get air to turn at the short turn.

What he said. You are much better off doing a very little as a gasket match and smoothing the inside radious of the pinch until you're past the casting roughness plus a little than doing anything in the bowl or removing the guide boss and have a performance 5 angle valve job done by a competent shop.