Has anyone tested both plenum and see which one is more consistent with speed and also which would produce the most power? I heard Michals plenum is about 60cc, is fx power plenum also 60cc? Michals plenum still use old valve system with rubber ball as backing. Which fx new power plenum replace the whole valve and rod system. I kinda like how fx rounded both ends on their plenum where as Michals it just look flat cut on both ends. Other than that they seem to be same sizes to me.