Thanks guys for the help. I haven't put any 19.5's on yet--I was wanting to check the collective wisdom here before doing anything stupid.
Bill, Yokohama came up dry, too. I have a 1-1/2 ton truck and according to the Chevy literature, the 850 tires require the 2-ton fenders with the larger wheel openings.
Jerry, Thanks for the info on the shape of the bead on the 19.5" tires. That was exactly the type of wisdom I wanted. Not sure what you mean by Farmers' co-op, though. The co-ops around here just own and operate grain elevators and feed stores. Do you have a phone number, web site or anything?
Steve, Thanks for the link to Miller tire. The smallest 20" traction tire they have is the 750's. They might work, but the overall diameter is about 5" larger than my 650's.
Probably my best bet for the long term is to start looking in junk yards for some 19.5 rims and throw on some newer radials. They look close enough to the originals, so I doubt anyone would really notice.
Again, thanks for the help,
Bob