Assuming the front end is tight, then the issue is either with the intermediate steering shaft, or the steering box itself.
Try what Jimbo suggested.
Been down this road already. Replaced the intermediate steering shaft assembly (there is a special kit) for $142, from Dal. Replacement took all of 10 minutes.
Found the u-joint at the upper end of the shaft worn (sloppy), and the layers of material in the rag joint were separating, which resulted in a lot of slop in the steering.
The new unit made a big difference, but I still had problems, so ended up replacing the steering box as well (but my ride has 130K miles on it). That made for very tight, responsive steering.
EDIT: Forgot to mention - no special tools required. When you go to do the job, best bet is to get the wheels straight, and then lock the column.
The plastic steering column cover unhooks from the steering box fitting and slides up out of the way. Then use a 7/16 socket to remove the nut on the column at the steering box. Use a big screwdriver or pry bar to gently move the column up, to disengage the column at the steering box. The other end can then be slid down to disengage the splined connection at the firewall end.
Note: DO NOT turn the steering wheel at any point until the new shaft is installed. You can damage the SIR coil.
Replacement is the reverse of the removal process. The spline at the steering box is keyed so the new intermediate column will go on correctly.
Hook up the firewall end first, then extend the shaft assembly to connect to the steering box. Tighten the clamp nut and slide the plastic column cover down and fit the ear over the steering box fitting again. Done deal.
Lastly - you will find more detailed info within the forum. Dare I say it - use the "search" function (ducking and running).