What Part is this?
 

I was driving the 79 300td and it starting pulling hard to the right. When I got home I noticed the right front wheel was toed in much more than normal. I jacked it up and placed on the stands and noticed this piece is missing. I think it is the outer bushing from the upper control arm, but am not sure. The bolt and every thing is gone. I appreciate any suggestions and course of repair.

That's the torsion bar, (the one bushing on that, UCA, is visible in the background) the end may be rusted away, there is a repair guide here somewhere, try a search.

There are a number of ways to fix that.
Replace the whole sway bar.
Drill and tap in a bolt.
replace the end with a replacement piece with bushings, has to be welded on.

http://www.activeboard.com/forum.spark?forumID=91042&p=3&topicID=17140497

http://www.peachparts.com/shopforum/diesel-discussion/144023-swaybar-repair-pictoral-300sd.html

http://www.peachparts.com/shopforum/1457785-post22.html

Charlie