The 9 bolt GM Borg Warner is an Australian rear that was used in Camaros from 1986-93, Firebirds from 1985-93, and Trans-Ams from 1983-93. This rear was a factory performance upgrade and is much stronger than the normal 10 bolt.
Does not fit a 10 bolt diff.
Cars with this style Posi have a 9 bolt cover.
From the internet:
"Most common "3 series" differential case number:
0578-908-F- 731 fits 3.27 ratios and numerically higher.
Should also be marked with Aust. Patent No. 222888"
Rare unit as most were 10 bolt.
$100.00 cash takes it away, no offers or trades.
If interested please reply with your phone number and I'll call you back.
I'll call you back after I receive your number.
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