I found two merchants selling F14 tubes. I just ordered 2 sets of 4.
Check these two links:
http://cgi.ebay.de/Weber-DCOE-DCO-SP...QQcmdZViewItem
http://www.dansperformanceparts.com/...ggyintake3.htm
Remember that after much testing on the road and under load a modified emulsion tube similar to F14 worked best on my 427 C/O.
The F14 tube has one advantage too, it has lotsa meat and is easy to modify, like drilling the interior deeper, turning the outside thinnner and drilling as many holes in it as you wish.
Good luck.