Here's a link to an easier way to find out whether you have a 6 bolt or a 7 bolt without removing a thing.
http://www.vfaq.com/proj-pics/oilpans-01.jpg (http://www.vfaq.com/mods/early-late-engine.html)

Click the pic to find out more info.

Compliments of our friendly DSM database, the vFaq.