Ok I'm missing a pin and I'm unsure on where to find one. .. it's the bottom one with the spring in this diagram that holds the two brackets together on one side. So fast looks like I'll need a drum also. Any help would be GREATLY appreciated

http://talk.classicparts.com/attachment.php?attachmentid=5052&d=1262896639


1964 impala ss
1949 chevy 3100