[66 L78 ragtop]

Interesting considering that Al Colvin's by the numbers states that the 323 block wasn't released until June of 67.

As a side note:
He also states that it is possible that some late 67 may have had 323 blocks, but then goes on to say that it would be highly unlikely and mentions that no 67 to date has been verified to have a 323 block.