Great stuff!
I'll post pics in two weeks of of our new plenum design for 3.6TT engine in this car:
http://forums.pelicanparts.com/showthread.php?threadid=254697
After lot's of thinking we went for twin-throttle dual chamber design with long runners and velocity-stacks inside each plenum.
You are very proficient at machinging things, ever tought about replacing butterfly's with slide-throttle design? I understand sliders are somewhat dirt-sensitive but it's probably even cheaper to manufacture than six independent butterflys and offers some extra performance to boot?