What brake line set should I buy 71 or 73

I have a 70 duster I upgraded the brakes on with 73 disc brakes so my question is do I order brake line set for 1970 or 1973 they will be manuel disc brakes my thanking is if I order for 1970 the lines to prop valve will be deferent than lines for 73 guess the question should be are the prop valves the same on 70&73 duster ?