You requested a 3" spacer, and it seems you have 3" of suspension lift so the height you gave me is acurate. I think what Crikey Mike was saying, and this makes sense is that as you seperate the diff mount from the A-arm there will be a slight horizonal change. So instead of just droping it 3" we should have offset the top and bottom plate a bit. This would be very hard for you to measure, I was hoping someone who is already running this set up would chime in.
When my bracket arrives try bolting it to the diff, then try bolting the A-arm on, if it seems like you are having to force it to make it go then we will need to offset it. Try to get a feel for what would allow it to bolt up and I'll make another one, it's very quick for me. Don't worry, I'm not going to charge you for something that doesn't work.
I'll see If I can work it myself by the pinion angle and the height.
Jim