I've seen rearends in cars off up to 1/4 or 3/8 inch shifted to one side of the car or the other....it makes a big difference.
with all things being the same under the car i take my measurements from the frame rails and get a centered measurement from there
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86 Mustang Gt......Mods piling up in my garage.
07 F350 dooly.....Tows my fifth wheel
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