I need the thing to fit the regular C6 case and an AOD case............
It's your choice in the use of the word "and" that makes the appropriate response to be: no such O.E. production thing, as the mounting offset is different between the two!
Now, that's not to say someone somewhere didn't assemble things wrong and get away with it; but this was probably due to the old adage of "two wrongs don't make a right", but it might make it work, sort of, situation.
I would assume the listing is incorrect or there is an add or subtract component (spacer) that is utilized with the appropriate transmission or unique converter required?
Best contact ATI and inquire.
But then, maybe I'm wrong?
Scott.