I have a 3.91 installed into a 6 speed limited, in Calf installed in 2015 ,, some of the 05 charger's diff has the same rear cover as the crossfire (mid year change i guess) because some did not ,and i machined the bolt hump/boss by 3/8" ( that is by memory ) i also have a 3.91 installed into a srt6 in Ft Lauderdale. I have a 3.64 from a 06 charger installed in a srt6 in Wisconsin . I have 3 srt6's and 2 limited with the 3.45 all with little to no modification ,, oh I also have a srt6 with a 2.86 installed all of these the owner can keep their original rear end because all were a bolt in turn key setup. yes the auto cars we did the TCU either a new one or reprogram their tcu Just trying to help you but looks like you have it under control. if u would like to know how to change the rear in under two hours let me know?
oh also i changed my first rear from the 307 to the limited 327 in 2011 .
the above had the srt6 yoke for the srt6 ca,r except 2 which we used the rear 1/2 of a limited drive shaft all the limited cars we did not have to change the yoke as the late o5 and o6--V6 challenger had the limited yoke,, note the V8 challengers had a different yoke.