[shommel]

between a 8 inch limited slip and a 9 inch limited slip?

 

[fastbck65]

1 inch. :smartass:

 

[Sick467]

Try this site. There is so much info, it'll make your eyes bleed...

Kevinstang's Ford Nine Inch Differential Page +

 

[andrewmp6]

They are two different rear ends.

 

[Chuck M]

The nine inch is stronger and will stand up to very high horsepower applications with only minor modifications. The 8 inch is perfectly suitable for most applications and will stand up to 350 hp without any mods.