This is 245/40.
Honestly, I'd try it if I were you. Take it to Discount tire, have them remove the tire, and slap a 245/40 on there, and see how the front fits. Should be fine on the rear. You'll roll the rear and remove the liner guarding the shock.
http://tapatalk.imageshack.com/v2/15/01/13/7f6d6e07ce358a47514422b5f05009d1.jpg