While I can appreciate that you'd like an answer as quickly as possible, cross-posting (i.e. posting the same message in more than one forum board) is frowned upon. It's confusing and often counterproductive. Please choose the forum topic that is closest to your post, and place it there only. If you should create a post in one forum, and later realize it would be more appropriate in another forum, please delete the original before posting it again. Duplicate posts deleted.
The engine number is stamped on the engine block itself. It positively identifies the engine size (e.g. A12) as well as the serial number. The mark should be on the left (distributor) side of the engine, but the location varies with the year. If you do not see the number, wipe the grease off the engine block.