They are complete heads casting number 3795896. A144 and A204. Jan 14th and 20th '64. NCRS accepts up to 6 months prior to car build date.
They are as removed from a friend's engine around 1970 or so, complete with well aged sludge and grease. One head doesn't have any rocker arms on it but the other still has the rockers and spark plugs.

If I remember right he had them on a '57 283 and took the engine apart to rebuild but that never happened.
If you are interested in them I can take them to my machine shop guy and have them cleaned and checked for cracks just to make sure they are worth shipping to you. I wouldn't feel right about selling an unkown condition casting.
Tom