I don't like the tubular the end on the firm feel is butt welded onto the large bar looks like it would need a lot to tear off.
Just called my mate Bill he has 13 cars & couple of Barracuda's he said he has a big box of old arms said a & B body are all the same.
I know my 72 B body & E body are the same bar don't know about the A body.
Pretty sure B body are different to the a body arm as they run a different ball joint. My a body arms are the big ball joint tho. The QA1 arms are very similar to the firm feel. Just not sure if my engineer will pass