There are a bunch of people in the C Body Dry Dock who are every bit as nuts about Cs as we are about Ys.
http://www.motorcitymoparclub.com
Scroll to Members' Discussion to reveal forums, then scroll to the Dry Dock
"home of the land yachts"
They also have forums for A, B, E and F body owners as well as wagons, AMC,
trucks, etc., but the Dry Dock is the most popular.
Also, don't forget the panic Tech Paper library at http://victorylibrary.com/mopar/mopar-tech.htm for excellent non-body specific Mopar engine stuff from the early hemi to the demise of the carburetor.