Welcome on board here. The 2-speed auto can't be shift kitted in the normal way. If someone has fitted the C4 auto, a three stage auto from the later cars, then yes, there are B&M Transgo shift kits for it.
The kickdown linkage may need adjustment could be lacking, or perhaps you've done some wild mods.
Aircraft technicians don't often push the safety envelope, I'm interest if you've hotted up the old girl!
(EDITED I made a mistake in what I said. A 2-speed isn't easily to shift kit unless you know what tesnion the springs are, and understand the way it operates. I'd say you'd have little chance of shift kitting it)