There are 2 types of JZA70 shaft, and 2 types of MA70 shaft. They overlap.
In other words, there are MA70's that came with the newer style bearing, and there are JZA70's that came with the older style bearing as well. They overlapped production.
All 86-89's are the old "M Joint" style, 90-93's can either be "M Joint" or "V Joint" for both the JZA70 and MA70.
The part number isn't the same as any other car, but that doesn't mean that an SC/JZA80 bearing wouldn't work, just that it has a different part number. I haven't looked/tried enough to know.
Jeff