Called Wheeler's the other day about their progressive AAL. They gave me the measurements:
Short side 15 inches from centering pin
Long side 18 inches from centering pin
Apparently there are different styles of TSB springs that were installed on our trucks. Mine is an 07 DCLB SR5 4x4 and has factory TSB leafs. The bracket to the front measures 17 inches and the rear bracket measures 16 3/4 inches, so I would have to cut one.
Just wanted to post this as an FYI so you can measure first and know if you need to cut or not. I'm sure there are others like me who would want to know this kind of info before buying. Hope this helps someone.