Best advice I can give is to get a helper, and have them turn the steering wheel wile you watch everything in the front end to see if there is any play in the steering linkage. You'll also want to pop the hood, and watch the steering shaft too.
If the steering box is worn, it can be adjusted, but doing so is usually just a temp. fix. And if you adjust it to tight, it'll cause the box to wear tha much faster.
It would probably be a good idea to raise the front end, and check your ball joints and wheel bearings too. To do this, raise the front end, and grab the tires at the 12 and 6-O-clock positions, and push/pull on the tire (or, place a bar under the tire, and try to lift). If it moves, you have worn ball joints or wheel bearings.
maroon 1987 Grand Wagoneer. stock for now...