8.75 or Ford 9”???

People seem to forget that the average nine was.....average. Ford built a lot of nines with gray iron centers, open gears, and 28 spline axles. An 8 3/4 was a better rear, in stock form. But ford also offered nodular cases and bearing retainers, decent limited slip (not great though, nowhere near as good as the clutch dana units) and 31 spline axles. That made the nine as good or better than the 8 3/4. Then since nines became preferred in nascar for easy gear changes, more ratios and stronger parts yet were developed. So now the nine has lots more parts and ratio selection, and can be as strong as your wallet will allow. That is not true for an 8 3/4 or a dana.