Tire Size?

[NewMStang]

I had a few questions in regards to the tires was getting, i was thinking of getting 275/35/18s (front) and 315/30/18s (rear)

-Is there any rubbing with either of those sizes (in front or back)
-Is 315/30/18 a bid to thin on the the width of the tire, I've heard that with a tire that large the width is the equivalent to say a tire 285-35-18, any truth to this?
-I can get rims 18x9 front and 18x10 or 18x10.5 in the rear (do i really need to go to 10.5 for the 315 tire size)?

 

[CobraRed_96_GT]

I wouldn't go over 295 on a 10" rear on our cars based on backspacing difference between a 10 and 10.5.
Those tire sizes wont rub, but that's about the limit.

 

[NewMStang]

any other thoughts?