Finally, after years of wondering what the answer was...Todd says it appears to him that these parts need slight modification (shortening of the 9/16" shaft/body) to equal the part supplied with the HA bar. Should be easy to do "at home".
You can get these parts from any GM dealer now, ordering with the GM 8-digit P/N's provided.
No--the bar would have to be modified, and you would need the link "adapters" for the control arm, too. These links are only for the HA bar that was built to use these parts.
There were 2 versions of the HA bar--what HA sold direct and what used to be sold by Moroso, as I recall.
Bill . . Thanks for this important info . . Now one question: Do the Moog (or for that matter, the ACD/GM) parts come in an M2 variant that has full support for the ball in the socket, or is this just a standard part that has several "fingers" supporting the ball?