Here's the way I did my bumper brackets for a 2" body lift on my 81 Wag.
The original bracket horns fit inside the bumper so there is no way that I can see for someone to make any kind of adapter bracket. You basically have to raise the bumper bracket.
I removed the rear brackets and straightened the part that wraps underneath the rear frame cross member in a vise with a crescent wrench.
Then I welded it 2" higher.
As you can see I needed to weld one side of the part that I bent down so the bracket wouldn't be too weak side to side.
The front brackets I cut off flush with the front frame cross member and used a piece of 1/4" flat bar to weld inside the cut bracket piece because there is nothing to weld to on the top half of where the bracket needs to go.
It was much easier than I thought it would be.