I have to think that Ford just wasn't up to speed on the stamps.
30 whole blocks out of over a million made, big sample!
As it was federal law to apply them, I seriously doubt Ford had the ability to opt out. That would be pretty much the same as saying many cars never got VIN stamps on the fender. Mandated assembly line practice, with serious fines for non-compliance.
Decades on the thousands of service blocks required by law do get swapped into older cars... Not sure of specific time frames but IIRC in the 60's manufacturers were reqiured to make service replacement parts for either 7-10 years, so Ford would have been cranking out blocks as spares for a long time....
Most likely a service replacement block. But have seen some indications that in some cases the VIN was incorrectly stamped on heads or intake, but not a common practice.
"True terror is to wake up one morning and discover that your high school class is running the country."
8R03S : 76A I 2A 15M 72 5 U
8R01S : 65A B 2A 28M 72 7 5 - Factory GT
8R01C : 65A M 2A 01E 72 2 W - CS/GT
8F01X : 65A I 2G 20E 24 1 U - EXP500 to-be