ok guys and gals i am trying to upgrade my open rear end with a new limited slip and gears. the only question i have is what is the factory one? i will post what i need answered. it is a 73 elky with factory 454 and th400 transmission.

1. it is a 10 bolt but what size (ie. 7.5, 8.25, 8.5)
2. how many splines are the axle (ie. 28, 30)
3. what gears were factory? (ie. 2.73, 3.08, 3.42, 3.55, 3.73)

thanks in advance cause i am soooooo lost on this one.