Because if you order for a big block you are going to likely use it in a big block. If you know the small block works in either then you could order and use it in either.
That makes no sense at all.
Point I am making is that there is likely an important difference or they would not make a BB version in addition to the SB one if the SB one would work in either.
Though I suppose it's possible one was designed first then much later the other was designed as well and not being Mopar savvy they didn't realize they didn't need both. See that often.
