Upper Ball Joint Question

Mine were both 198/904 column shift plain Jane animals. No options at all. They were rubber mat cars, so, the floors were rusted out. That's how I got them as parts cars. They both had original paint and interiors, so, pretty much untouched. I got them in 1982 so, unlikely anything had been changed on them....and they both looked it. I had orders to fill from individuals and brake shops for those hub and drums as they had been discontinued by Mother Mopar, and the aftermarket didn't have them. I believe the "crossover" as 72bluNblu mentioned was when they discontinued the 9" brakes altogether and only made the 10" brakes from then on. Like I said, look in the factory parts book. There is no before and after date for any of those spindles, ball joints, or control arms.