Thanks for the help. Intermittent automatic transmission sometimes it wont move in any gear.

I understand,,,,it’s easy to trip up on if Mopars are new to you .
Even most off brand mechanics don’t fully understand that part .

I’m assuming you already were running the transmission ?
Why did they change the converter ?
Or was it just because it was a 360 converter and they removed the balance weight ?

Either way it needs to have the fluid changed and filter swapped .
There could have been contamination when the trans lines were removed .

After that I suspect an issue with the valve body .
Trash in a valve or just a sticking valve .

Tommy