What width Dana 60 for a 70 Dart?

oldkimmer said
It also depends on what wheel offset ur gonna use. Factory a body 8.75 width is 52 5/8s flange to flange (outside)plus or minus 1/16 inch. Kim

That 52 5/8 is for 1 7/8 brakes. The big bolt pattern axles sticks out more and uses 2 1/2 brakes.
The dana housing I'm building now for my duster will be about 51 1/2 housing flange to flange.