1966 Dodge D/Dart ~ 'Mystery, Myth and Misconception'

I was curious, I thought I read that they used late 50's hemi valves in the 920 heads because they were slightly bigger. In 66 the 273 was the only LA engine so there were no 1.94 or 2.02 valves. Just wondering.
Stock 920 heads. They used the CAP engine.