To complete my entry...
If you take my design#2 (see page 4 in this thread), add the swirler in the intake, and re-arrange the rest of the fins to accomodate the swirl, this block might perform very well, with a lesser flow.
I'll have to figure out how, but I'm ready to start experimenting with it. I just need a fellow CNC'er to help me out with it...
(once I've tuned the swirler and fins).