I have a 2017 ram 1500 with a 5.7 and 3.55 rear end. The specialist sheet says may towing is almost 9 thousand pounds.
I am looking at a 5 th wheel that is 7600 dry weight and paylost of 2300 pounds hitch weight of 1321. If I install the balloons on rear springs would it be possible to tow.
Possible? Yes. Safe? Going to argue no. The number of fifth wheels that don't put a half-ton truck over its payload AND RAWR are slim to none depending on the half-ton.
The other thing you need to think about is that that's usually the ADVERTISED dry weight and DRY hitch weight, you might get the specific dry weights to the camper 'as-built' but anything added to it throws that number right out the window. The reality is, once you're loaded up, there's a strong chance your camper is going to be closer to 8500 lbs for a weekend and have a hitch weight MUCH closer to 1800-2k lbs since most of the storage in an RV is in FRONT of the axles, not over or behind them.
A lot of the guys in half-tons you see pulling fifth wheels are either older trucks that they've beefed up (or came with leaf springs in the rear so they're a bit stiffer anyway), OR they just don't care and added air bags to level it out, despite being way overweight. Same goes for a lot of 2500's - you can get most of the 'half ton towable' fifth wheels behind them but there are some that are out of reach.
There was a time when yes, half-ton trucks could handle fifth wheels, because a 'camper package' made them almost a 3/4 ton. That's just not the case today.