Backspacing question

Move springs, like blu says.
Then I'm guessing, a 6" bs, add a spacer as required
I run a 10 inch rim and over a 13" section with a 4.5 BS on a 3" narrowed rear. So that's the flanges moved in 1.5 per side. And 1.5 plus 4.5 = 6
IMO that's not pretty on a Mopar.
You want a 10 in there? My best advice is to move the springs,narrow the rear, and measure it up, for custom wheels. Then prepare for some massaging in certain areas.
Or you could go oldschool............but you'll get no help from me,lol.