I agree it is ez to search for the answer to this one. While it is true the dorf rear ends are not gm, they are sort of a standard when it comes to hotrodding. It is valuable information to know how to ID a 9 inch.
All that being said, I don't know why anyone would want to buy a used one and rebuild it when it is so cheap to get a new one made. The 9 inch rear can be made in any length with almost any lug pattern, any size and style brakes, any gear ratio and any type of traction enhancement. Not to mention you can have one built specifically to match the HP of your engine. It seems to me it would be a lot eazier to have one made to your specs than to hope to get lucky with a used one.
