Post your wheel and tire combos.

How far are you moving the springs? 3" or 1/2"?

I have 295/35/18's on 18x10's on my Duster in the stock wheel wells with a 1/2" offset and some trimming on the quarter lip. Backspace is 7", but that's on a 68-70 width B-body 8 3/4 rear.

They're only a 12" section width though, I'm pretty sure you'd need a mini-tub to run anything wider, I'm maxxed out with less than a 1/2" of clearance to the springs and quarters.