tires in the wheel wells

i just bagged my 53 belair and im running g78 15 white walls and my tires are in the wells before the car is layed out. my question is what size tire could i run, that wont hold up my car with out cutting out my wheel wells. And if i had to cut the wells out, how would i go about doing soo(pics) but i really dont wanna cut them out. thanks for the input

 

any thoughts

 

205/70/15 worked out just right on mine