i have a 1968 mustang coup with no suspension modifications. ive been looking at foose legends or torgue thrust M in 17 inch. i have looked at a lot of mustangs but hardly ever see what size tires and if the car is riding on factory suspension. i want to fill the wheel wells but not rub or stick out. i want a lot of wheel but not too much and only have a tiny bit of side wall on the tire. if i did an 18 inch would it rub, and would the side wall be too little to work? also whats the right backspace, offset ect.