strange block date code????

[oldgal]

G'day,

I was just under the gal' preparing to remove the tired 390 to make room for my rebuilt 428 when I spotted the date code on the 390 block.  Very strange, it has no date but does say "SPEC"?  Anyone come across this before?  What does it mean?   It is a C4A block, correct for 64 Galaxie. 

Thanks in advance...

Will post some pics of the casting later and I have a heap of pics of the engine build to be added.

Cheers,
Phil.

[turbohunter]

Howie will jump in here as soon as he reads this.
He's a SPEC block kinda guy

[oldgal]

Thanks Marc,  I hope someone knows what it means