383 Body manifolds in an A?

Jim Lusk said
No such thing as a 67 383 with HP manifolds from the factory. The only 67 HP manifolds were found in 440-equipped B-bodies (GTX, R/T, and Charger).

The manifolds pictured right above are 68-69 C-body HPs.

He might have seen a '67 casting date on the block and assumed it meant it was a '67, when it probably would have been used in a '68 application?

I've noticed the casting date is usually a year earlier than the car it was installed in.