Big Tires

Hello everyone. I am new to the Nova and its unibody construction. I am use to the full frames of the Chevelle which I know the most about. My first question is:
I am working on a 72 Nova and I was looking to put bigger tires on it, something like a 15x10 on the rear. I know they will not fit on the when it is all stock, but what if I would move the frame rails in? Would that work or would it screw up suspension? What would be some other ways to fit that size tire? I was planning on putting a Ford 9" in it also.
Thanks for your time and any replys.