whoops, that should have read "would contact", not "wouldn't contact".
crawling around in the dark, I get about 9" from tank to axle in my shortbed. Not exactly much of a comfort margin. plus with all the differences here and there (hangers, fill spout), I think you'll be better off with a new tank. To the best of my knowledge, no one has yet installed a 23.5 in a shortbed.