Porting DC Stage IV iron heads

I forgot an important point to make about the Stage IV and V heads. With the combustion chamber, the bowls, the roof and the floor similar between the Stage IV and the 452 heads, and the the similarity in the same structures between the Stage V and 906, then pushrod pinch really doesn't mean squat. The ports are stopped up beyond the pushrod pinch, and it of itself, isn't the problem.