Monumentally stupid upper ball joint question

Thanks - ahead of time - for your patience. I just bought the Doctor Diff front disc brake conversion for my 1967 Dodge Dart 270. The front brakes had been 9" drums.

I purchased the upper control arm ball joint adapters as a part of the package. Here's the stupid question (drumroll please!) -

I need to buy an upper ball joint to fit a '73 or newer A-body for this, correct? As in, I can't use upper ball joints for a '67 upper control arm, correct?