Anybody running 17" Cobra Bullit rims on a Duster

The terminology on "offsetting" the springs can be deceiving. A 3" spring relocation is one thing, that can have a pretty big effect on body roll. But, you can also offset the springs with a 1/2" hanger and shackle kit, which increases tire clearance quite a bit without really having a big effect on the body roll. Certainly nothing that can't be dealt with using an adjustable rear sway bar, especially since the need for a rear sway bar on these cars is pretty minimal to begin with.

I call the 3" spring relocation a "relocation" and not an offset, that way I can call the 1/2" hanger/shackle offset an "offset" and not confuse it with a relocation. Clear as mud. :D

I don't see a problem at all using a 1/2" offset. And, if you aren't planning on mini-tubbing, the 1/2" offset gets you as much room as you're going to get with the stock wheelhouses anyway. Also, keep in mind that Dr Diff calls his hanger/shackle kit a 1/2" offset, while Mopar Performance calls their A-body hanger/shackle kit a 3/4" offset. Both are actually about a 1/2", that's really all the room there is. But even with a 3" relocation you can deal with the effects of moving the springs. Stiffer springs or a larger sway bar can both help deal with that roll, and of course if you're running tires wide enough to need a mini-tub your suspension needs are going to be totally different anyway.

I run a 1/2" hanger/shackle offset on my Duster with a 68-70 B body rear and 18x10" rims with a 7" backspace (38mm offset) and 295/35/18's. On a Dart though a 1/2" offset will only get you to a 275 wide tire, you need the full 3" relocation and min-tub to go bigger than that.