The templates are designed to port to the maxium limits without any breaking through into walls as you talking about.I looked at the templates and wonder why it is like that. I am curious how they measure up to the actual heads. I know my heads have a sleeve pressed in around the head bolt area and the porting is done around this sleeve. The templates in the book would not be as large as my heads based on the lack of this feature in the template. The template appears to blend around that area without maximizing the port size.
Allan G.