Ok, What have I done now... (904 problem?)

This could be a quick or slow fix. From my experience, as an old farz, that has played with Mopars since 1968;did you drain the converter? did you drain the cooling system? If not, over 12 qts is way too much. But then, I only been around the 60's to 70's stuff.Just helped restore a 440, 727, all new parts. Trans, converter, rad, and aux cooler. 11 qts total. Don't understand how yours wants so much fluid.

While pan is off, check the shifter claw for adjustment. Then read about the governor. I Dunno.