Just a reminder, and it's in many past threads on the forum...
I wasn't happy with the steering control on the '95 F350 w/ 80,000+ miles. Driving on the highway I'd have an inch or more of play before the wheels would grab. The steering gear box adjustment is the easy and cheap thing to look at first. Remember on worn suspensions it can also be alignment, ball joints, wacked A-frame, etc whatever else on your particular vehicle might affect steering.
On the top of the steering box (by the radiator) there's a set screw and lock nut that adjusts the steering tightness.
Overtightening causes too much gear wear and hard to turn wheel, so just take it a quarter-turn clockwise at a time, after you loosen the lock nut on it.
Mark the position of the set screw first with whiteout or etching tool, so you know where it started.
Some boxes have an allen head screw, mine is a slotted round set screw for a flatblade screwdriver, with 5/8" locknut around it.
It took only three tries, 1/4 turn each time then drive it for the feel, for a total of three-quarters of a turn to get it right. Made a world of difference, now the steering is responsive again, woot!