IFS drop spindles on 65-66?

I WAS WONDERING IF MUSTANG II DROP SPINDLES WILL FIT ON A 65-66 STANG, SEEING THAT THE BALL JOINTS ARE THE SAME FROM ABOUT 63 TO 78. I WAS READING IN A BOOK WHERE SOMEONE WAS SWAPPING AN IFS FROM A 77 STANG INTO A 70 MUSTANG BUT WANTED TO MAINTAIN THE STOCK DRUMS AND IT SAID THAT THE BALL JOINTS WERE THE SAME.
SINCE THE SPINDLES FROM A 70 FIT INTO A 65 STANG, AND THE 77 FIT INTO A 70, WOULDN'T IT BE POSSIBLE TO PUT 77 SPINDLES INTO A 65 MUSTANG, THEREFORE BEING ABLE TO PUT DROP SPINDLES FOR AN IFS INTO A 65-66? AM I WRONG OR IS THIS POSSIBLE?