It depends on the brand of tire, but I would say yes. I have run a 315 Nitto on a 9" rim and a 10.5" rim.... But a 315 BFG is way too big for the 9" rim.
I Will Prob. Use A Mich Sport To Match The Front Since There In Great Shape. Maybe A 305 Would Work. The tire rack web site said you need a 10.5 inch rim for a 315 tire..