Just going to throw out the obvious, as I'm sure its been checked and rechecked.
Since the rears are off set centering pins in the rear of a mini truck (meaning the axle does not sit in the center of the spring), did you make sure you have it in the right way?
Thats what it looks like to me, but I could be wrong.
Other than that, I got nothing.
Baby Beast 2- 1999 4Runner SR5
Baby Beast -1987 4Runner SR5-Gone, but not forgotten