What size 10 Bolt Rear-End In 1969 Pontiac Firebird.?

[PFB1969]

The car originally came with a 350 2bbl and limited-slip
My question is what size 10 bolt came stock?
The 8.25 or 8.75?
Can my rear end hold up with my new 455 with 475 horsepower?

 

[melsg5]

Check this link www.oldsmobility.com/10bolt-tech.htm it appears you have a 8.25 As far as I remember all GM divisions used the 12 bolt rear on anything over 400 cid

 

[Goatman]

There was only one 10 bolt up to 1971 and it was a 10.2" it was a decent rear but would only hold around 300-350 ftlbs tq so it would be marginal with a 455..
the other rear available only in a Camaro was a 12 bolt unit and they are Rare and expensive ..