The 8.8 I put in my '40 it's from a 2003 FX4 Ranger I think they have 4:10 gear,posi and 31 spline axles mine does. 4:10 times .7 for OD and it's back down to a decent ratio.
1990-1992 Ford Ranger 8.8-Inch Axle - 56-1/2 inches
1991-2003 Ford Explorer 8.8-Inch Axle - 59-1/2 inches
The spare one I have is the explorer rear. These should be plentiful in his area. In my opinion 9" are just overpriced for what they are. The 9" center section I just sold was a 3.5 with a posi. The guy drove 3 hours each way to buy it for $475. 8.8's are cheaper then that IMO.