3970010 engine decode help

[indianachevy]

I acquired what I was told was a 1969 350 that was taken out of a 1956 Chevy Belair in good running condition to be replaced with a 383 and 5 speed. 

Casting number - clearly 3979910

I'm having trouble making out the casting date to confirm what this engine was when it left the factory.

There are several groups of number on the passenger side of the block, but not in a format I thought I would see based on some of the documentation I read online.

One group appears to be 6 D 8

What appears to be a clock, pointing at 3 o'clock

A1
DN

Stamping on front deck is hard to make out, seems like: K04 09 FXD

[indianachevy]

Casting number

[indianachevy]

Stamping on front pad

[ZLP955]

Looks like TXD to me?
If so, that was used for C and K, 20 and 30 series trucks from '75 to '77.

[WorkinProgress]

It is a truck engine. 1975 350, 165hp, 4 barrel

                          - Warren

[Stingr69]

The T in the suffix gives it away as a Truck engine and the fact that it has a 3 letter suffix tells you it is not '69.  '69 uses a 2 letter suffiix code.  This block is from the 70's.  The VIN derivative is probably under the paint on the stamp pad to the left of the assembly stamp.