I’m late to post this info, but here it is for those interested.
I made a 4 part DIY over a year ago on how to refurbish and repair a 1963 C10 steering column. Many sections will apply to 1964-72 columns as well. The 1960-62 columns are different animals but still have similarities.
The original design of the lower bearing is not very good. A brass bushing or sealed lower bearing is much better.
The DIY has 4 sections.
https://lugnutz65chevystepside.weebly.com/steering-column-page.html