I have an S60 in my Duster. Have 4.30 gears and 4.56 already on spools. Really doesn’t take that long to swap gears and is certainly cheaper than a whole after market “pig” set up ready to swap. If you do go 9” do your homework on a housing that will hold up. Ladder bar kind of hard on stuff. My rear including rotors/calipers is 198lb.