Yea I ha e the 31's and spacers on it now looks good. I new to lifting trackers or anything. What do I need drop the diffs
You need to replace the stock diff hanging brackets with longer ones. Calmini is the only one I know that commercially makes longer mounts, and that comes in their complete kit (which they DO NOT SELL PIECES OF). You will have to make your own longer mounts. The drivers side is not hard to figure out, just make a longer one. The passenger side hangs at about 30 degrees and you want it to drop down, so you don't just make it longer (that would shove it back and down), you have to rotate the mounting holes so it goes down only,
Seems the simple thing is just to lengthen stock mounts, rotating the passenger side a little and welding them back together, but they are cast and not welder friendly. They will break at the weld when you need them the most, or at least one will. 1/4" X 2-3" flat stock with a small stiffener would work fine.
As with all modifications, one change needs another change. With longer mounts it is easier for the diff to twist (or not twist as the frame twists) as you are utilizing all the flex you have created, and the diff is made out of aluminum (which doesn't flex much) so then the back mount breaks off the case. Now you get to make a mounting bracket to hold it in place , and there are kits out there to fix broke back mounts. It is better to make it before it breaks.