The 4-cyl never used the AW-4 tranny. The 6-cyl bell housing is larger and has a different bolt pattern, so you cannot bolt a complete AW-4 and bell housing to a 4-cyl engine.
I don't know if it's possible to adapt an AW-4 to the 4-cyl auto bell housing. In fact, I don't even know if the 4-cyl auto HAS a separate bell housing. Even if you can get the tranny to mate to the bell housing, you would probably have to do something to adjust the length of the input shaft.
I know it sounds tempting to use what you already have available, but in this case I don't think it's a good solution.