Registration and Posting Agreement
http://www.ntwonline.com/69-87_GM_STEERING_ARM_P13345C324.cfm This is the one you want.
Once you get the arm on or even before, I'd double check the calipers. Pull them back off and make sure one side isn't siezed(the side that it pulls to). I'd also rebleed them. Air in the line could prevent a caliper from working properly. Hope you get the bugs worked out.
Man those folks are slow. Do you buy from them often? I bought mid-day Monday and still have not shipped. Very slow.
Possibly the box or adjustment. Does all the way to the left? If so, pull the drag link off and see if it goes past the arm on the left side. This would indicate that it needs to be centered. I ran into something similar and if I remember right, it was when I pulled the arm off the steering box and didnt get it back on right. It was a long time ago, so I dont remember for sure.