What "makes" a 66 Barracuda a Formula S ??

Maybe the new owner of that '65 exec car will join FABO and post a photo of the windows sticker. :welcome:
Sure, no argument. Manual disc brakes option too.

10" drums were standard on V/8 cars in 1965 also...
Nope. I've had many '65's with 9" drums, including Commando/Charger 273 cars.