WVXC450R

I have my leveling kit and I have a set of 35's I'm wanting to get on soon. However I also have two pro comp 1069's brand new in a box. They're 17x9's with a - 6mm off set on them. It doesn't say how much backspacing there is and I'm not 100% sure how to figure it out. I know I need factory back spacing to run my 35's with my 2.5" level kit. Will my km2's rub on a set of the pro comps like that? Or do I need to stick to stock wheels?

Sorry guys. I know every other post is about leveling kit and will I rub and what size. I promise I searched before I posted!

WVXC450R

I was able to find that the pro comp wheels back spacing is 4.75" but I'm still unaware of what factory is.