how much narrower do you need? an early 90s 8.8 wont bolt to the drive shaft(90-92 8.8s) and they ahve a smaller axle bearing. get one from a 95 up ranger(should be bout 1.5 narrow,3/4 on both sides, maybe more) and your brakes should all bolt on there since they have the big bearing, but i dont see y u wana give up the 31 spline axles...
I dont want to give up the 31 spline axels but I was wanting to run a wider rear wheel/tire combo and have a nice deep dish to so thats the only reason for the change short of ordeing a custom housing/axle shaves