If you have the stock (old)brake parts, measure the fillowing:
Inside diameter of the bores in the wheel cylinders
Inside diameter and width of the drums.
Width of the brake shoes.
Different models had different size brakes. The parts stores today sometimes have measurements but don't always relate them to the specific model, ie, GT, Sedan, Wagon, Engine Size, etc. with the measurements you can check the parts at the store before taking them home. | 
