Try and find someone with an A-body that wants it!
The earlier B housings are shorter, as you mentioned. That makes them the best fit other than an A-body housing for the A-bodies. And since A-body housings go for twice as much (or more!) than B or E body housings, its a fairly common swap. The later (longer) B body housings require more backspacing in an A body, so they don't work as well. My understanding is that even though the perches are a little wider, they can be made to fit without relocating the perches by opening up the location holes in the perches.
I have a '65 B body housing for my bronze car