I think you may have misunderstood my post. What I meant was it would have made more sense for ford to just use the larger 8.8 diff from the ST/platinum and put in a torsen for the timberline, than to commission a torsen for the smaller diff used in the XLT/limited. No one here knows for sure what size diff is in the timberline yet. The pic posted earlier does not have a diff tag so we have no idea what it actually is. I hope it is an 8.8 in the timberline, that would be so much simpler for all of us.
As for the ratio, They all get a 3.58 ratio except the platinum, which gets a 3.31, so the XLT, Limited, Timberline, and ST all get a 3.58
BTW I think a torsen out of the 15-22 mustangs would work, but they are not cheap.