235/60/15 on front of duster?

Here's a post were @autoxcuda said max backspacing on a 15" rim is 4.5" with a stock UCA.

73-76 A-Body Offset

That would push the tire in another 1/4" from where mine ended up.

So maybe a 15x7 with 4.5" BS would work?

One thing you could try is one of those online calculators and plug in a know wheel and tire combo on your car and then the new sizes and see how it moves the tire around. Based on that you could get an idea of how well it might fit.