A few years back I was looking at a manifold for my A12 road runner and I wasn't sure if it was a production line or over-the counter manifold (it had the standard 6, without the CH6B). Before purchasing I contacted Darrin (Big D A12) and he told me there were multiple runs of the Edelbrock intakes during the production of the A12 cars. Some had the wavey 6 (early production) and some had a standard 6 (later production), and both the wavey 6 and standard 6 are accepted as production line correct.

Some more info here.
Link