What you're looking at in the pics on the link you posted is not the ported intake manifold. The pics show that the head ports have been gasket-matched. The intake manifold is installed on top of what you see. Gasket-matching the head ports is only necessary if you do install a ported intake manifold as it eases an abrupt step-down in port size. The gasket-matching has been said to be worth a few HP on ICEolator installs with stock intake manifolds. The ported IM + ICEolator has been said to have a combined gain in the range of 30HP.