This is my understanding, too. One could order 10" brakes (HD brakes) on a /6 car. IIRC disk brakes on the front would put the larger drums on the rear axle. The best way to tell is to run down the build sheet to determine what was installed at the factory. However, if the car has been in the hands of someone like a FABO member, anything could be on the car. (lol)