A 305 x 45 tire is over 12" wide...there would definitely be a clearance problem re suspension components eg front coil lower mount...this size tire would be approx. 3/4" outside the wheel wells...
I don't think I'd go with a 9 1/2. I would certainly bolt one up before mounting a tire - but I'd be really surprised if it'd fit and be able to turn the wheel lock to lock.