David, The other thing that comes to mind is that with an 8X20 is that once converted your camera will be limited to that size unless you purchase or build a reducing back. Additionally the ability to rotate the back will probably be compromised. For those reasons, it may make more sense to have a second camera. Possibly buying some old beater 8X10 off ebay after checking that the metal is all in workable condition and then converting that to the larger format. I visited with a fellow, in France as I recall, that was converting a NFS 8X10 Deardorff to the 8X20 format. He said that he really wasn't having that much difficulty since the Deardorff can be converted without building an entirely new rear swing bracket. At any rate, Good luck. Now you have my juices flowing...Those big negs would sure be nice on Azo and Amidol.

Best regards,
Donald Miller