The parts store will have a listing if you tell them car, engine etc. Battery cables are sized by length and also gauge. You must have the correct gauge or the wire will be too light.
I agree with the first two posts but I have, more stock ford cabling is not great go with a lower guage wire (lower guage bigger wire) and replace both wires with the same guage wiring. It is good that you are replacing them before they give you trouble. My ground wire went bad and gave me all kinds of charging blinking and other drama before I figured it out! Oh well good luck!
Also, the book at Checkers says to use a wire length that is substantially longer than what was in my car. My friend went with what was in the book, and ended up having to bundle up a bunch of wire behind the coil cover...