1967 GTO engine block

[Andre]

I went to go look at a HO equipped GTO today. I checked the engine code and the 6 digit engine sequence numbers. The code was correct but the 6 digit was off by 1 number, for example PHS # is 000289 and the block was 100289. The thing that made me run away was the casting number at the lr of the block was missing. Anybody ever come across a block that had no casting #? Only thing I thought of was a restamp to make it correct.