Dude you have to work the chamber wall, especially when you go to a larger valve! The pinch won't show you anything until you unlock seat area (bottom of the valve job to the deck).
Thanks for the nugget. I always appreciate the input and welcome the advice.
In defense of what we are trying to achieve with this thread, we are trying to take steps that the average guy at home could take in modifying heads with inexpensive or readily available tools. Each modification will then be flow tested to see the improvement or lack of improvement. So far, we have been avoiding deep port modifications, serious bowl work or chamber work. In the end, we'll probably have to go there.