The bolt-in lump doesn't go all the way to the rear of the port wall, they only stop about 3/4 of the way in. There are many ways to improve the flow on the divided port idea. The slotted washer fits on the topside of the divider in the original head bolt boss and the screw-in plug holds it in place. My friend Darren's port dividers were much thinner, and this ports were already opened up wider for racing. They were already over 320-ish CFM before he divided them. There is a lot of untapped potential in exploring this.
