WHAT REAR END WILL SWAP IN MY 1965 DODGE DART

IIRC, In the later part of the 65 model year they became standard on early A's IF equipped with the 273/235 engine AND a 4 speed. Reason was too much warranty work on the 7.25's when coupled with the higher HP motor and a 4 speed. The 273 2 barrel still got the 7.25. I parted out a 65 GT with a build date of 7/23 that was originally a 273/235 with a 4 speed. The 8.75 in it had a date code of something like 7/1 or so. Still have the housing which is going in my 65 Barracuda.
IIRC, the a-body 8-3/4" was also used in fleet sales, as in for taxi cabs. Just like the rear sway bars for a-bodies was a fleet only option in '76 (?).