(Pardon the mess, this was the garage as well as the shop I had.)
I realize it was a strange beast, but it did the trick. Yes, my test pressures were extremely low (3"!) because of the motors I was using. (They were free, what can I say?) I still managed to pull numbers, even though they weren't super accurate, I still managed to "come close" with this bench. It flowed both exhaust and intake. The bottom tube had the pitot in it;
I even made a simple manifold for switching out the lines when I swapped from intake to exhaust;
Alas, this bench is long gone and has been for over 3 years now. I now have a full blown shop (not just a small section of my garage) and a dedicated area for my NEW flowbench that I have yet to build - which brings me back here! I've been reading posts galore and have been formulating a new design. I'll probably be posting some design pictures to get opinions on here soon.
I have already picked up 8 vacuum motors off Ebay (they are some cheap made in China ones, but I think they will work.) They pull 90" of static when blocked off entirely but I have no specs on them further than that. If I can get 300CFM @ 28" of test pressure out of them I'll be happy at this point.