Some pics located here:
http://www.bionicdodge.com/bionic/index.php?topic=6705.0A possible easy way to reduce plenum, volume would be to put a 'brick' inside the intake. Obviously you'll want to use a material that can withstand the temperature and not sluff off any material, but otherwise just stick something in there.
You could fill it up with large ballbearings, too, and then fish them out thru the TB with a magnet stick. An easily-adjustable variable plenum -- if you didn't mind the funny noise.
