According to this article, the max GVWR is 6250 which you didn't list for your particular truck.
https://en.wikipedia.org/wiki/Ford_F-Series_ninth_generation I'm surprised that it only weights 4300, but if that's right for your truck, you'd be under of the very max GVWR.
The key is where the weight is though. You would need to go to a scale to see how much weight is actually on the rear.
'10 Ford F-450, 6.4, 4.30, 4x4, 14,500 GVWR, '06 Host Rainer 950 DS, Torklift Talon tiedowns, Glow Steps, and Fastguns. Bilstein 4600s, Firestone Bags, Toyo M655 Gs, Curt front hitch, Energy Suspension bump stops.
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