Drums and bolts for a 91 sedan
 

So my parking brake locked up in the drum and I'm trying to take it off of the back plate. It's your priceless New England junker with rust and seizing issues so I need to use the bolt method of slowly pushing the two apart. Haynes says use an 8mm bolt with nothing in regards to the thread and Chilton just says use a bolt (thanks a lot). After trying every 8mm the local hardware store has and after pulling various ones from around the car and trying them, with nothing working thus far, I'm here asking you guys for help.

So, does anyone know either the thread pitch and size I need for a 91 rear drum or know of a bolt I can pull from somewhere on the vehicle that would work. Thanks in advance.

-Kienan