Finally got around to installing my Magnehelic this weekend. Just a quick job solution, but it works. Whole system is brand new still and you can see the needle at about 0.5" when running with one port open.
Still havent run a support wire/cable off the plenum, so thats why the stool is under the filter, to support the weight of the filter. I also still have to get the bin sensor circuit figured out. Got the Banner sensor installed in the drum lid, but havent finished laying out the circuit to do what Im planning yet. Ill post that in the bin sensor thread when its done though.