Centering rear wheels in opening.

rowinafour said
The hanger does not add length, it is modified for offset. The spring perch locator moves the axle back. The bottom plate needs the locator hole offset to allow the ubolts to properly align.

Ok. I'm following you now. What did you do to the frame to gain access to the spring eye nut/bolt.

I was thinking of drilling a hole in the frame big enough to slide the bolt through and sleeving it to add strength.