why a Ford 9"?

I thought the Ford rear ends had more resistance than the Chrysler ones... also isn't the carrier interchangeable on 8 3/4s too?
yeah. I was just doing some research and it seems to me the numbers that count (bearing size, pinion size, etc.) favor the 8 3/4". made me wonder. one thing the nine has to its advantage is the cost and availability. Ford's main concern, it would seem, was production numbers.