Axle offset

Mike, it's been my experience that these older vehicles very seldom measure exactly the same from the centerline of the diffy to each outer fenderwell. The difference could be in the spring mounts, there may have been a meeting with a curb or other immovable object in an earlier life, or there may be a difference in the quarter panels themselves. Take a measurement from the centerline of your diffy out to the exact same spot on each wheelwell to see if you get the same measurement. I've owner several 55 Chivvys since the mid 60's and each one of them have different measurements side to side. Hope this helps.