2014 F-250 6.2 with 4800lb front springs and the 3 leaf rear "standard duty" (non-camper package) suspension.

I'm pulling a 5th wheel toyhauler, total pin weight is 2100 lbs. I've already added Air Lift loadlifter 5000 ultimate bags on the rear, but I'm also considering ordering the heavier duty leaf springs from the F-350 and putting them on the truck to support the weight. I can't find the documentation on what part numbers correspond to the ford suspension package the trucks came with, or where I can buy the F-350 parts.

I'd also like to go up from the 4800lb front springs to the 5000lb springs. Realizing that this is going to make the ride quality when unloaded pretty crappy.

 

There is no difference between the f250/f350 rear springs on a srw truck, only the f350 dually has different springs that hold more weight. I'd simply go to a spring shop and have them add a leaf to your original pack. A framer I work with has a 2wd 2013 and 4x4 2015 f250 regular cabs and he had a spring added to each truck and it made a huge difference. Before he would pull into a job with the rear bumper almost dragging from just ladders and tools. Now both trucks sit stock unloaded looking, I feel the ride is just as good as our bone stock 2014 f250 4x4 at work

 

I just put the Tuff Country Add A Leaf on my 250 this weekend. According to the company it adds an addition 1200 lbs of load capacity (not to be confused with the actual payload as rated by Ford on your door pillar). It makes my truck sit about 1 1/2 to 2" higher in the rear and I do not notice any difference in ride as of yet. but it is more stable feeling.