Hey, I wasn't criticizing your use of English, you write fine from what I can tell. Most people refer to the unit as a "spindle" but it isn't the correct term. It's just like calling a limited slip differential a Posi when the correct term for Mopars is Sure Grip.
Are you sure? I'm not. I've seen drum brakes on A bodies as late as 1976. Maybe they modified the 73-76 Drum knuckles to match the mounting points of the disc units?