1964 PLYMOUTH VALIANT N.O.S. FRONT BRAKE LINES

You need to google it for yourself, but my understanding is all the 6-cylinder A-bodies had 9 inch drums. The quote below is from a google search I did.
"Our 1964 Dodge Dart GT convertible came from the factory with manual 9-inch drum brakes all around, on 13-inch wheels. Even for a '60s machine, this was dismal; today, it's completely unacceptable. The slightest amount of heat will degrade stopping distances, and dodging today's SUV drivers, who take electronic stability and braking aids for granted as they idly chat on their cell phones at 85 MPH, practically mandates stouter stoppers in our elderly 45-year-old A-body."