77 REPU - stripped control arm bolt
 

So I found my first real problem with my repu. I was under the truck and noticed the drivers side lower control arm bolt was loose. I went to tighten it but immediatly recognized both the bolt and nut were stripped. I going to try and find a replacement castle nut today since it looks like I may be able to get it down to the good threads (about 1/2" is messed up) but im thinking replacement would be best. I thought it was just a long bolt but it has a collar at one end that bolts to the subframe and a single bolt through the middle of the "bolt" at the other end. I dont have a picture of it removed because once I pull it out Im going to have to compress the springs and I want the truck movable until I goto replace the part. So here are my questions:

1) What is this part called? Im calling it a control arm bolt but its not a simple bolt?
2) I know they made changes to the 77 suspension from earlier models. Am I looking at a 77 only part? Any suggestions for other similar vehicles that may have this same part?
3) Anyone have a 77 parts truck with a drivers side control arm thats good?

Front side of control arm bolt (good threads).
http://i29.photobucket.com/albums/c2..._arm1_edit.jpg

Back side (stripped) of control arm bolt.
http://i29.photobucket.com/albums/c2..._arm3_edit.jpg