Here is a view of that archway shelf on the intake transition bend. It is actually sticking out into the opening. It is excess material left over from the machining of the head casting to locate and install the valve seat insert and to dimension the rough casting into the bowl and transition bend. I definitely have some metal to remove here; and some smoothing and blending to do.

Also quite visible is that little step at the roof of the CC; which I will grind flush.