I am thinking of getting a 5th wheel. Can be at a weight up to 16,000 pounds. 38 feet long. I have been told the F250 and F350 have the same engine. I would prefer a SWD vs Dually but not sure yet. My question is: What is the major difference betweem a F250 SWD and a F350 SWD?
The one ton has an additional leaf spring in the rear suspension giving it the added weight capacity. I tow a fifth wheel with mine and it performs beautifully... I definitely recommend the 5th wheel over regular tow behind. I had a tow behind before I traded up to 5th wheel and it is a dream to drive. My truck is SWD and it does all I need and then some. No need to enter the dually realm in my opinion, you just get more truck which costs more to own over the life of the truck (think about the additional tires, lower mpg, possibly more money at the toll booths and higher yearly registration cost increases...) Unless it is a working truck that really needs the heavier capacity in an everyday way, the SRW should do the trick. The only downside to 5th wheel vs. tow behind is losing some/much of the space available to you in the bed while towing, and the inconvenience of the hitch attachment brackets in the bed the rest of the time.
At 16k depending on how much hitch weight there is you might have to have a dually to be legal. Mechanically speaking no real difference though, and same spring packs available for both (overloads that are standard on the 350 come with any of the optional suspension packages on the 250 also).
Poor dead horse, he's gonna get another beating.... This has been researched by several folks.
There were a few rear spring packs used. Which was used depended ONLY on the body style and options specified on truck.
F250 versus F350 had nothing to do with it. A 250 ordered with the same equipment as a 350 appear to have gotten the exact same springs. Just a thicker block, a different rating on the door tag, and a higher price on the 350.
It is possible more
Back to the OP's question....
With that large of a 5'er, you will most likely need the ratings of the 350. Depending on the specific coach, possibly even need to get 350 DRW or 450 to be within legal ratings (if that matters to you). Especially if you haul passengers and stuff in the truck bed (like an auxiliary fuel tank or firewood, which is surprisingly heavy). Some coaches have a LOT of pin weight.
I assume you already know that published axle and pin weights of RV's are almost always blatant marketing lies?
I ALWAYS recommend insisting on getting new RV's actually weighed before signing the bottom line. 10-20% over published axle and/or pin weights is not uncommon. And once you load up your things, it gets only uglier.