I don't think there's a Mopar specific club in Temecula or or Murrietta. There's the Mopar Club of San Diego, but they tend to look down at "lowly" A-Bodies.
Bob Gough the Mopar Club of San Diego club president drives his 67 Barracuda everywhere. I've seen it covered in dirt from road rallyes and such. He also has a Dart. There's another member, Steve, that has a Australian Valiant and his teenage son has a 71 Dart project. Jim Signorili (sp?) races a Duster.
Sometime you can run into one member that is not representive of the group. Or many time claims they are a member when they are not. Or not an active member.
I suggust going to a Mopar Club of San Diego meeting or function and make a decision for yourself.