I found these on ebay, Firestone collectibles, he has a lot of stuff, worth checking out. Appears to be all decent, and prices are average.
http://cgi.ebay.com/ebaymotors/Mopar-PCV-Valve-63-64-65-66-67-68-69-Dart-Charger-GTX_W0QQcmdZViewItemQQcategoryZ34202QQihZ002QQitemZ4628937569