Whatever year it’s not important, I’m not arguing the OP’s situation , if that 2500 indeed has that low of payload . I’ve never had a fifth wheel that was over 15,500 , and never towed any of them with anything less than a 350 Ford or my present 3500 Ram .
I’m sure I wouldn’t get on the internet, and admit to what you’ve done , that’s Darwin Award time . That fifth was far into dually territory. No I don’t think it’s fine to tow over the weight ratings . But unlike you before I towed my first fifth wheel , I knew what truck was needed . I realized I may go bigger , which I did . I didn’t even consider a 3/4 ton , went with the 1 ton , although I didn’t need a 1 ton at the time .
I repeat I still get a laugh out of you , and the rest of you weight police, please go back , and read ALL of my replies , not once did I tell the OP he could tow that fifth wheel , I did say he could tow it fine , just couldn’t haul it . So you can get off YOUR soap box . I know now , and knew 20 years ago what a 2500 could do, and could be modified to be as capable as a 3500 , and I know now the new ones cannot , but I repeat I’ve never told anyone to tow over their trucks ratings .