Swapped to Muscle - 75 Duster Daily build
Left Axle is 30.6875" long -
https://www.randysworldwide.com/product/ya-f880015/
Right axle is 27.8125" long -
https://www.randysworldwide.com/product/ya-f880014/
Cross shaft is .875" -
https://www.randysworldwide.com/product/yspxp-026/
That puts it at 59.375" wide before putting brakes in it. With drums, I think that puts it right at 59.9" wide, but I expect a rotor will make that 1/8" wider or so.
Based on
Moparts on the Web - Main Index the 65-67 B-Body 8 3/4" is 59.5" drum to drum.
Not sure on the offset beyond the above math that the axle lengths are different by 2.875". I know it has been done without too much trouble so the offset can't be too terrible.
I looked at doing this a long time ago. Even tripped over a Mustang 8.8 housing for cheap that I bought. But in the end, didn't follow through (don't remember why though). It's been so long now, not sure where I would even find the notes I took or the posts I made.
I ended up settling for an 8.25" out of an F-Body to get the width I need for the 17" wheels I am running.