You said, you have stock wheels and want to keep them, but you ask for wheel size?
I'm confused... but I have 275's on back of mine, and 225's on front. The tires don't rub and there is a little bit of space left between the qtr panel and the tire.
Now, if you want wheel size, I have 15x8 and 15x7 and both are 4.5 bs. The wheels I have are ProStars, but don't have any pix on here of the car with the new wheels, but in my signature you can see the tires and stock wheels still on mine. The pic labeled, "onthewayhome" is the one to look at. Hope that helps and got any pix to put on, i'm sure everyone would like to see them.