Somewhere I read that a 74 cam is better than an earlier cam, with a little more overlap and more advance (to help with the smog crap) but I dont see where Mopar reduced the CR since 1963. There is a place in Oregon that regrinds solid slant cams to almost anything you need (within physical constraints of the stock cam core they use) so they can increase lift and duration, and to a lesser extent overlap for a mere 70 bones.
http://slantsix.org/forum/viewtopic.php?p=191616