One thing to watch if you are going to do that is when you cut the upper plenum to short down, it is basically impossible to weld it from the outside. As well you will lose the 1/2" of the flange added on. As you can see from the angled up big plenum one there are pieces of tube welded in because that is the only way I could make it to keep the A/C and still have the big bad ass tapered look! So you may look at that before you hack the top manifold but just a thought!
Thanks,
Seth
Thanks,
Seth