Seller added a link to more photos:
https://drive.google.com/drive/folde...xV?usp=sharing
The block does appear to have the 65-only "fangs" on the front, but still no shot of the all-important deck stamp. LOTS of stuff wrong and/or missing under the hood too.
Also note the two plugged holes in the firewall, suggesting it had dealer or aftermarket under-dash AC at some point. Possible in an L78, but relatively unlikely (as compared to dealer AC installations in hydraulic lifter cars).