My steering column is incredibly loose at the "tilt." I've removed the steering wheel, turn signal mechanism, and ignition switch, but can't seem to get at the root of the problem. To eliminate the hassle I've got my eye on a complete replacement column. I have manual transmission. Any idea what the going rate is for a replacement?

I had the same problem on an '88. There are four bolts that come loose for the tilt mechanism. You can tighten two of them without taking the column completely apart. I found this link to be helpfull when I did mine.
http://www.chevyasylum.com/column/tiltcol.html