going with a dakota transmission
The pans on the A500 and A518 look identical to a 904 and 727.
Here's a link to a page that shows the different automatics with pics of the pans. The pics of the overdrive transmissions themselves look to be 4wd trans. with the transfer cases off. A 2wd model looks similar but tapers down on the back end and has an output shaft just like a 904 or 727 depending on if it's a A500 or A518
http://www.mymopar.com/index.php?pid=108