I went out today and removed the ball studs from my old 51 steering arms. I was only able to remove the tie rod ball studs. The stud that the drag link attaches to on the left steering arm would not come out so easily. I am wondering if it is threaded in or not. However, it appears that one side is larger than the other (tapered fit). I can see the outline of the crack in the metal where the stud should separate from the steering arm.

right side ball stud removed: http://good-times.webshots.com/photo/2197542980100058208MXeiTP
53 and 51 steering arms (note no taper in the 53): http://good-times.webshots.com/photo/2535098260100058208bvIBKG
Another view with the new tie rod end: http://good-times.webshots.com/photo/2037724820100058208TrXBhk
Ball removed from LH steering arm: http://good-times.webshots.com/photo/2037724820100058208TrXBhk
Here's the problem I had with getting out the ball that goes to the drag link on the LH steering arm: http://good-times.webshots.com/photo/2982782630100058208htCZWX
I can't tell if it is threaded or not, but one side seems larger than the other: http://good-times.webshots.com/photo/2445794590100058208zbBxpK