The model of car you can fond from what if found and it may take more research is an 82-85 500 sec , it had that differential if your looking for a swapped rearend, I remember hearing you needed to swap your flang over.I would like this swap for my 300d turbo with a factory 4spd , I spend more time on the freeway here lately , it should put me at 75 mph with a 3100 rpm , I’m sitting at 3300 rpm now and would like not to push these old cars . Being a slow driver by today’s standards , 60- to 70mph , the engine likes lower rpms by its nature .