How about Jeffrey Hunter as Jesus in "The Bible?"

Elizabeth Taylor as "Cleopatra."

In the 1950's movie "David and Bathsheba," the actor playing King Saul was about 5' 6" (or so it seemed) and quite chubby. Saul, according to the Biblical account, stood "head and shoulders above" the men in his army.

Also, when the 1950s movie version of "The Brothers Karamazov" was filmed, utimately starring Maria Schell as Grushenka, Marilyn Monroe desperately wanted the part and, I understand, was seriously considered for it.

I'm told also that Ronald Reagan was the first choice of the studio to play Rick in "Casablanca."