8.8 swap

Did anyone ever say if a mustang 8.8 is the right measurement for a Duster? I've come across one that is 5 on 4.5 with posi.

What year Mustang is it out of?
I would think that they would be too wide. It would be like a C-body rear in your duster:
94-98 Mustang 60.25"
99-04 Mustang 61-5/8"