my duster has a 9" from a mid 70s merc. it is real close to a 8 3/4 with welds at 6.5 back space.
springs moved in and wheel wells extended to the frame. plenty of room for 10.5 slicks. i run 30" and had the rear quarter cut at the center of the wheel well to the door and moved front 1.250" to clear the front of the tire.
it looks factory now with 30x10.5 slicks under.