The link that ROMI provided is the North Oakland Mopar Muscle club website. I was a member of that club for several years. There are a LOT of great people and fantastic cars in that club.
Unfortunately, they only meet 3x per year, so it is hard to talk to people or learn much. Each of the three meetings was mostly about organizing the next event, and almost nothing about the cars. I ended up dropping out of it, because I was learning a lot more about my car on this website! (I don't mean to slag NOMM...It just didn't work out for me)
I wrote to Motor City Mopars, but never heard back from them. Since their website hasn't been updated in a couple of years, I would guess they might not be around anymore.
That's all that I'm aware of. Good luck to you!
-Tom