8 3/4 axle offset a body brakes, DeJaVu?

Because of my recent Dimentsia...please set me straight....LOL

Stock a body 10" 1.75" drum brake set up VS. b body 11/12 "2.5" drum brake set up

So, axle offset difference is only 11/16" (eachside)of overall track difference? between them?

On early A it makes a difference even with springs at rail.For keeping bigger tires under car.
I thought it was more........

Thanks, Dave