This is on my ’88 K5. Some of the older steering boxes won’t work with this swap due to having a bigger splined end on the steering box. I don’t know the years or models off hand, but I’m sure someone on here does.
Once I got the shaft home I took the two halves apart and cleaned it up and painted it. The shaft that I got had plastic inserts that kept the two halves from moving. I just drilled them out and threw away the inserts. The pic’s below show where I drilled and where the inserts were. The holes were already there. That’s where the plastic inserts had nubs that stuck in there.