'65 Formula S always have 10" inch drums on front or some had 9"?

In 1965 you could order a brand new Dart 270 4 door sedan with a 273 and automatic transmission. Came with 9 inch brakes. My buddy Johan owns it. Second owner.

I have a 65 Dart GT that came with same drive line. 9 inch brakes all around. Both these cars was assembled in October of 1964.