When you put the fronts on the rear they don't turn any more so as long as they clear the suspension tower or coilovers you should be fine, right?
I'm assuming they have a substantial offset wheel spacer/adapter keeping them out that far, 315's are fairly beefy even for a 10.5" wheel.
The fronts (cobalt rear), if they're that large, will probably most definitely rub when put on the front... at the A-arm at least at full turn, because mine do as do a few others.