My truck, a 65 C10, had this same issue. Many times the area on the steering shaft the lower bearing runs on is badly worn and the lower bearing or bushing replacement won't fix it. Plus, it's a hell of a lot of work to get the steering shaft out.
I fixed mine by installing a nylon bushing in the lower portion without taking the shaft out. It's been working well for 3 years now. It's not really a bushing, it's a nylon quick release tool.

[img]https://i.ebayimg.com/thumbs/images/g/oIUAAOSwLl5eRDK8/s-l200.jpg[/img]

See it in there? chug

[img]https://i.postimg.cc/PJqc1V2v/image.jpg[/img]