I am wanting to know the differences between the posi's of 9 bolt and 10 bolt factory. Also can some tell me the easy way to tell for ebay pictures such as this one http://cgi.ebay.com/ebaymotors/ws/eB...477417805&rd=1 which I think is a 9 bolt.

 

They are completely and altogether different.

That one looks like a 9-bolt, not the one for a 7.5" (10-bolt).

 

i don't know the differences, but i know you can't swap the posi from a 10 to a 9 or viceversa. i have a posi 9 bolt and my unit doesn't look like that...

it says at the top of the page camaro/firebird 7.5 82-92. i think thats a 10 bolt unit.

 

That's a 9-bolt one.

There is no guarantee of sellers's technical descriptions on ebay.... they're just as prone to mis-identifying stuff as anyone else. The mere fact that he said that's what it was doesn't mean squat.

Here's a 10-bolt one.