I agree with the others, if you're getting flashed with that minimal amount of squat, they're probably ain't too high from the factory. I would try to adjust them a little bit lower for starters and see if that helps. Also agree with the others, glad you're addressing the problem instead of just ignoring it and blinding everyone.
Is it common for an F-250 to squat that much with 700 lb of tongue weight? On occasion I pull my travel trailer without any weight distribution hitch hooked up, and I have maybe that much of squat in the rear. It doesn't move hardly much at all.
