Just FWIW and nothing else...
I pull an Elevation 3912 5th wheel. It's 41ft long at weighs in a 13,500 (approx). I pull it with a 2013 RAM 2500 SRW 6.7 Cummins. I added air bags to the rear, but probably didn't need to.
My truck pulls my 5th wheel easy and tows it straight like a dart.
Like I said, this is only FWIW and your mileage may vary...BUT...I wouldn't think twice about it. Pulling a 5'er you need to consider your PAYLOAD...not the tongue weight.
Having pulled several very heavy TT's, IMHO a 5th wheel is cake.
easy decision, IMO.
