15x10 fitment on non-tubbed Duster

Hi folks, looking for some advice and discussion on putting 15x10 Keystone's on Arthur's Duster .
The situation is this, I have a couple of 489 cases I can build with different ratios. I have several C-body housings at my disposal from a friend to choose from.
For Arthur's Duster I would like to stick with Day 2 mods and resist the urge to put 17" or 18" wheels on it. I have always loved the Keystone look and think of all the Day 2 wheels (US Mag Slots, Cragar S/S, ....) they look the best. Problem is they only come in one offset per wheel width.
I was planning on upgrading from the 8.25" to the 8.75" anyway so a custom length rearend is not out of the question.
The wheel housing on my Duster is 12+ in wide so a 275 or a 295 could fit.

This red Duster I found on Moparts is the look I'm going for but I would not mind if I had to keep the rear raised a little higher than that. That car looks amazing.
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"It has the Mopar 3/4" offset spring kit. Caltrac monoleaf springs minus 1 inch with rancho shocks.15x10 Billet Specialties with 5.5 backspace,275/60/Mickey Thompsons,stock width 8 3/4 with drum brakes.The outer wheel lip was trimmed.The front is stock except for caltrac 90/10 shocks and the 318 torsion bars lowered to within 1/2 inch of trimmed bumpstops.When pics were taken it had 165 metric radials on the front which were a little over 25 inches tall. We now have Hoosier 26 inch front runners. Stock inner wheel tubs. "

My car has the 3" inboard leaf spring relocation but I would like to put the Doctor Diff spring relocation on it so I can route the factory exhaust under it and use OE exhaust tips.

The Keystone's 15x10 only comes with a 4.125" backspace. Should I be talked out of this or proceed forward with buying the wheels to start mocking up and measuring for the rear housing width?