Sorry we are not being of great help for you so far, but it doesn't mean we're ignoring you, just that we have been having trouble getting the info you need.
Anyway, if you're still looking here, see the following info from Bob Dillon:
Originally Posted by Bob Dillon
Lash: Tell the guy to e-mail my buddy Jim Hand at firstname.lastname@example.org
and mention my name. Jim has been around Pontiacs since the 50s and if anyone will know, he will.
Jim has written a book on high performance Pontiac V-8s and is one of the nicest guys you'll ever meet. And if Jim doesn't know, his brother Floyd will.
I'm sure the answer will be "no prob" on replacing the guides with solid guides and stems.
I can't imagine anyone notching a valve stem. It sounds like a recipe for disaster to me.
I hope this helps.