904 won't do anything
Transman probably nailed it! If your trans was built before '67 you will have an 18 spline input shaft. A '67 & up non lock-up transmission has a 27 Spline input. If you put a late converter in an early trans the oil pump will be driven but the input shaft will not. Don't ask me how I know this. LOL. Here is a photo of the 2 different input shafts.
![29750939es.jpg 29750939es.jpg](https://www.forabodiesonly.com/mopar/attachments/29750939es-jpg.1715067894/)