I know there have been some other threads on this subject, and as some have cautioned, don't over do it. Also, if you have a lot of play in your steering, look elsewhere first. Steering Box Adjustment is generally indicated by slight vagueness in the steering. Such as a slight amount of left right play at highway speeds, but no real pulling to one side or the other or a lot of shimmy in the steering.

Years ago on the older Fords and the Chevrolet Vegas I used to play around with, this was a common high mileage wear point, and it can help quite a bit if you have the conditions described above.

You have to drop the front splash pan (that is some THICK plastic!), using a 15mm socket. (I was working on a 96 blazer two door.)

Once that is out of the way, then look up on the drivers side in between the frame and oil filter and you will see the nut and stud sticking up. It helps if the vehicle is on a lift, but can be done lying on the ground.

Depending on how the nut is turned, you can get a 16mm open end wrench on the nut enough to loosen it. Some cases you "might" have to remove the oil filter. Before you loosen it, take a 4.5mm short leg Allen wrench and fit it in the top of the stud.

Back the nut off 4 or 5 turns while holding the Allen wrench in place to make sure you have enough adjustment.

Start turning the stud in with the Allen wrench, until you just feel a slight resistance on the Allen wrench. Stop at that point and back off a 1/4 turn and tighten the jam nut back down while holding the Allen wrench and stud in place.

I had a veteran GM mechanic years ago tell me this method, and it has always worked for me.

I just finished adjusting mine, and it took away a lot of the vagueness on the highway and sharpened up the low speed steering some as well.