The
GM Turbo 400 used in quadra-trac equipped Jeeps had an AMC-specific case with an AMC patterned bellhousing and is not interchangeable with the GM
GM Turbo 400 's without an engine to tranny adapter. The early pre-AMC
GM Turbo 400 's used the BOP bolt pattern and had a factory adapter to make them fit the 225/327/or Buick sourced 350 in the respective jeep. That adapter will not fit an AMC patterned block.
The
GM Turbo 400 was used in '72-'73 Commandos as well as '72-'76 FSJ's with AMC engines and
Dana 20 transfer cases. I am 75% sure that they also used an AMC-specific case and bolt pattern. But it is possible they used an engine/tranny adapter.
You can bolt an actual GM tranny to an AMC engine with the proper adapters:
Adapting AMC I6 & V8 Engines to GM Automatic Transmissions
Remember that this only bolts the AMC engine to the GM tranny from a 4wd GM as a 2wd
Transmission from a Camarrow, etc... requires even more work. Even starting with a GM 4wd
Transmission you would then need to have the appropriate GM
Transfer Case or further adapt the GM
Transmission to your original jeep
Transfer Case . The possibilities are numerous. The same is true with a factory Jeep
GM Turbo 400 : if it was not originally attached to the
Transfer Case you intend to use you will probably have to adapt/modify it to fit your
Transfer Case . The
GM Turbo 400 units from quadratracs will
only fit the '76-'79
QuadraTrac and the one from a
Dana 20 jeep will
only fit a
Dana 20 ( super rare 1980 IH-only
Dana 300 excepted) without such adapters/modifications.
You can get a '80-newer AMC-patterned 727
Transmission from a FSJ that will bolt to a
AMC 304 and to the
Dana 300 you list in your vehicle description. You can also get the auto that was actually installed from the factory in a 1980
CJ7 : the AMC-patterned 904 (not recommended for V8's) or 999 that will work with a
Dana 300
Keep in mind that if you have a GM Turbo 400 /Dana 300 in your 1980 CJ the tranny has been swapped in and has had to been adapted and/or modified to fit that Dana 300 as there was no GM Turbo 400 /Dana 300 factory combo! The Transmission may also have been adapted to your AMC 304 . Do you know what the original application of your parts are, or know how the components were made to work together? 
