Ya know I might be getting the choices confused. I just sold one not long ago to a buddy in Canada and seem to recall it being open, but maybe that was the Predator version?!? I cant seem to find the pictures but for some reason I thought they had both depending on how old they were...I cant see the "tent" being any help, I suppose the thinking behind it was to help direct flow to the 4 cylinders on each end?!? Seems like a bad way in my mind to build a tunnel ram but maybe I'm wrong.