earliest 67 3916323 block?

[snydes]

Hard to fake a casting date and the fact that the block is machined for a canister filter. Clearly Mr. Colvin's research was incomplete at the time of that statement.

[66 L78 ragtop]

He may have changed his initial position...The book I referenced was his first edition.

The aug cast 323 block that I made reference to was from a 68 L78 Camaro with a 02B TT date. I looked at that car with the intent to purchase but backed out because of the discrepancy between cast date and stamp pad date.
The stamp date was jan 68. After I backed out of the deal, I later read that up to 8 month difference in cast vs pad dates were not that uncommon due to strikes in 1968...?

What are the odds that the car had its original block considering the time difference between cast and stamp dates? The pad looked real

[snydes]

That is a large span, I once had a untouched '71 LS5 engine that had a long span like that between cast and build, if I recall correctly for the same reason, some sort of strike going on at the time.