We need someone with a ‘71 hardtop to take a measurement. I have a convertible too and although I haven’t tried too hard I have not found a bar that will hold the lid up more than a couple of inches…
That looks to be the torsion bar crossmember in @Challenger RTA ’s picture, looking rearward with what looks to be a piece of tube welded to the backside and continuing rearward like a frame connector? Either way or whatever part that is it needs to be completely replaced if you’re into doing...