1972 dart 360 with 904

And I bet Precision of New Hampton could come up with what is needed. Those guys are tops.
That's because it's a stupid representative picture someone put there. If it does not have a ring gear on the converter, it is not for a Mopar transmission.

Summit sells weighted Mopar converters everyday.
Nope - not single one listed for a904 is available on summits site right now .