widest tire with spring relocation

I have a 67 dart and the widest tire I can fit is a 255/60r15. just want to know if I can fit a 275/60r15 if I relocate the springs only without mini tubbing it. if I mini tub it I will want to narrow the axle, I may do it later but at least maybe get a wider tire under it for now. any knowledge will be appreciated. thanks
i have a 73 and we moved the springs in and used the spring relocation kit to move them in under the frame , and i want to say i have just enough room for the 275 , but another thing we did was moved the spring reward like and 1.5" , so we basically altered the wheelbase , because of front wheel well clearances , and this made it nice . i have aftermarket quarter panels on the car and the wheel lip seems longer than stock going toward the tire , and my tire rub a little in tight cornering , going to have to roll the inner lip to stop the rubbing , we also shortened the axle , so now the wheels have a deep dish to them . im also in michigan ,see ya ed