Brian, you have touched on several areas that peak my interest here. I have played around with undercutting the chamber wall. For my feeble attempt I did gain some low lift flow but hurt flow after about 0.350"-0.400". I love the idea of the steep top cut angles and would enjoy a conversation about how to make that work on this head with factory 15 degree top angle. I have played around with it by sinking valves. There are so many other things you have touched on that I would like to discuss. I fully understand there are limitations on time and information sharing. I'm grateful for anything you add.
I'm going to hold off on the chamber modifications until we are finished with our initial steps 1-5. We'll try some more stuff later. I also want to try one final blending of the valve job to the chamber walls, but I will also hold that until the end of steps 1-5.
One question for now. These factory Speedmaster heads have a top cut of 15 degrees. The factory Edelbrock RPM heads that I have are cut with a zero degree top cut. Without sinking the valves or welding the head, is there a way to incorporate a steep top cut angle? This is especially a problem on the chamber wall side (the area you marked in yellow). On the SM head, I had to sink the valve 0.090" to get rid of the factory 15 degree cut in this area.