Sent you a PM but here's a couple things to keep in mind when narrowing a truck diff. As I mentioned in my PM, there are a number of truck Danas out there that have larger axle tubes and can be an issue with the U bolts. When installing the spring perches most people know to check the pinion angle before welding them on but not everyone remembers to align the new axle tube ends. The flat part of the tube end should be parallel with the ground when the diff is in the car. This is important with drum brakes but not so much with disk. The reason is that when the backing plate bolts on with the wheel cylinder, it has to be parallel to the ground or it is very difficult to bleed it properly.

Here's a shot of the truck diff we narrowed and installed in my Charger.