I didn’t. I just pointed out I don’t really care for 4 hole to open tapered spacers. In my at the track testing the antireversion plates almost always went quicker and I never had one slow down. But the manifold has to be opened up to make sure it doesn’t cover any of the groove around the outside. If you don’t open up the plenum to uncover that groove it will go slower. I have no idea of the science behind it, I just know they work.