My plan is put an 8' bed on my 41 3/4 ton, from a '66 Jeep. I've measured it several times and know I will need to make several modifications, including adapting the mounting brackets/braces. I'm also putting dual wheels on the rear axle, so I will need extend the rear fenders out to accommodate that, as well as modifying the running boards.
All that is to say, you can do almost anything. "Is it even worth the trouble?" you ask? - - - - I'll let you know when I get it done.