how much difference, 250 x 350?

taken wrote:
To answer some of the OP's and subsequent poster's questions here goes. This has been discussed ad nauseam on many RV forums and has been clarified 100% on the Ford fourm FTE. The difference (other than the door jamb sticker) between single rear wheel 350's and 250's are two things and two things only. The 350 has a 4" rear spring spacer block vs. the 250's 2" block. The second difference is the 350 comes with an upper overload spring. (This can also be ordered as an option on the 250.) Everything else is 100% identical. Same frames, brakes, axles, differential, etc. For a while in early 2011 the 350 SRW trucks had hydro-boost brakes but now share the vacuum boost brakes with the 250. So, yes, if you're ordering or buying new, you may as well spend the $900 and get the 350. If ever you go to a state that weighs private rigs, this may come into play. (There are VERY few of these.) If you are buying used you can do what I did on my 09 250 and what many others have done to eliminate sag. Swap in taller spring blocks and add airbags or an overload spring and you've got the same truck albeit not on the door sticker...

As to why there are also 350's with lower GVWR's, it's so you can own the truck in certain states that are heavily regulated without paying more registration, insurance, and inspection fees based on a high GVWR.

PS: If you're wondering how I can say without a doubt that they are the same, I've done what a few others recommended when I wasn't sure I believed it. I looked up all the part numbers between the 250 and 350 and found them to be identical.