Howdy all, first let me apologize if this has been covered but i cannot find a post telling me exactly what i want to know.

I am wanting to purchase some new rims for my car, and ive been eyeing 18x9.5 black c6 replicas on ebay for my car. I looked around to see if i could find anyone that has an 8.5" for the front anywhere but i cant find them that are competitivley priced.

My questions:

First i will let you know that i have done the LS1 brake upgrade on my car.

Will this affect my selection of a wheel spacer? If so, then in what way?

Im looking at putting a 255/35/18 tire on this rim. Will this tire even fit on this rim? Secondly, will i have major rubbing issues, and/or will they not be able to tuck under the fender?

When i put my LS1 brakes on, i started rubbing a little on the drivers side when fully locked to the right, but i hit it a few times with a mallet and it clears now. fyi

As far as the back goes im looking at a 285/35/18 tire, as far as fitment goes im confident that it will work out.
But, will these two tire sizes work together alright?

According to the tire calculator the sidewall difference is about .4" from small to big. And the overall height is about .8".

Thanks in advace for any help/advice.