Originally Posted by SmokeyWren
Depends on the WDH. With a cheap or undersized WDH, you're right. But with a good WDH such as an Equal-I-Zer or Blue Ox SwayPro or Reese Strait-Line rated for a max of 1,400 pounds tongue weight, properly adjusted to return the front end height back to near the unloaded height, you won't have that much sag in the rear end. A properly-adjusted WD hitch will leave only about 50% to 60% of tongue weight on the rear axle. So that 1,250 pounds of tongue weight gets distributed so that at most 750 pounds of weight is on the rear axle.
I'm speaking from 1st hand experience working with a 2016 and a 2017 F150 wiith a 1050lbs tongue weight, using an equalizer hitch and an Andersen hitch.
With 1050 lbs of tongue weight, using the WDH to reduce rear end sag to the point where it isn't so low that you look like you have a ton of bricks in the bed (2.5" of sag) puts way too much weight on the front axle, so much so that steering is adversely affected. Properly adjusting the WDH and reducing tension to bring the front axle back to stock weight leaves you with 3.5" of sag in the rear. At that point, bumpy roads cause the bump stops to hit the axles. Not good.
The solution? Air bags. Air bags in the rear solves the sag problem, but still doesn't stiffen up the rear end enough to handle the other effects of a heavy trailer. It's a decent ride, but not great.
So no, the standard F150 is not built to handle 1000lbs of tongue weight, even if it looks fine on the internet.
Also, max tongue weight is limited to 1220lbs, so that 1250lbs is over right from the start.