Early A Body rear axle housing interchange questions.

I am new to early A Bodies. Had later A Bodies for decades. Need some information from folks in the know.
Is it true that I can take a 7 1/4 or 8/ 1/4 large bolt rear end from a Scamp, Duster, or Dart and the rear end is a direct bolt in right onto the leafsprings on my 65 Barracuda and the rear end is the same size drum to drum? Picked up a nice Barracuda and found the previous owner did a disc brake conversion on the front in large bolt but left small bolt on the back. Thanks in advance for the info,
Chas.

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