Adjusting for play in steering

[dzwestwindsor]

I have a 1971 C20 that has a good amount of play in the steering. It's definitely because of the steering gear, since the input shaft going into the box can be rotated by hand without any resistance, and with no output.

Is it safe to adjust the allen screw and nut on the gearbox? I've seen people write that it is dangerous and may lock up while driving, or that it wears out the box even faster. Are these claims true?

If I adjust it a little to remove some of the play and still be able to rotate it from full lock to full lock without any issues, it should be safe, right? It wouldn't just randomly lock up without warning, I hope?

Thanks