The rear shackles on ’83-95 minivans are the same as AHB (yours).
The ’96-07 minivan rear shackles are close, but not quite (as you have pictured in post # 30). The newer ones are metric and studs are smaller diameter. A person would need to find a way to sleeve the difference on stud diameters and inner rubber bushings. I hadn’t looked at the newer shackle for width or tallness but would expect them to be about the same.
I have three good used ’83-95 minivan shackles, if you experience a broken stud or yours is too rusty.
The important part is to get under car, maybe a couple of times with a liberal dosage of penetrating oil at these locations, before disassembly (will make the job a lot smoother) at yellow arrows.
Fasteners at white and red circles (not visible) need to be gotten, as well.
Another item that helps is if your existing fasteners are rusty (like yours are) is to clean what you can using a thread cleaner. These look a lot like taps/dies, but these to not make new threads, but to clean existing threads (a big difference). You do not want to create new threads out of your existing threads – which can happen if using taps/dies (I’ve done it and have ruined a few fasteners that way).
They go by several names: thread cleaner, thread restorer, thread chaser (and maybe a few others). I have a metric and SAE sets at home and sets are about $35 each. I “believe” a person can rent a set from the local parts store from me. Well worth the money if you work on old cars.
In this case, I would use a thread cleaning die on each of the fasteners after they been sprayed (a few times). The thread cleaning tools can’t do anything for the rust between stud and nuts, until the nuts get removed – so that part will still need to be man-handled (carefully).
Not often do I see rust inside of the rear frame rail affecting the rear spring hanger bracket to frame bolts (white arrows, below) – so in most cases, those should be ok to remove. If they don’t come out easy, you might have to drill a small hole in frame rails to get the rust penetrating oil tube inserted, for soaking.
Note: the rear spring hanger is wider at the blue arrows, for the AHB (trapezoid) hangers. This rear spring hanger fits FMJ cars only. You can see the difference in width between the straight and your (AHB) bracket.
The aftermarket does make a very stiff (but straight) shackle, as seen in post #33 – but they don’t work on your brackets.
I agree with others; your parts do appear to be rustier than I’d like. I understand the appearance of rust and being rusty are two very different things, so I can’t tell if that will be an issue for you or not (based off picture on post # 30). For what I can see, if the nuts come off, I would say you are fine with your existing shackles.
The rear frame bracket – might a bigger concern.
If both items ae serviceable, I would definitely clean the items and give ‘em a good coat of paint before reinstall.
BudW