Help decoding block

[Gary68]

I have an H440 8 12 stamp on front.
But on side it says 2536430-9 and date code is 3 1 71

Seems to be 1972 but dated mar 1 1971 . Is that weird?

 

[PurpleBeeper]

That seems normal to me

 

[R413]

Normal. Blocks cast ahead of time. Machined on 8-12-71.
They start making 1972 cars in august 1971.
They start making 1972 engines and trans in July 1971

 

[69Coronetrt]

Not weird at all. Pretty much a block is a block is a block. It's the components that make it model year specific.

This particular block got cast, put in inventory, didn't get used for MY '71, sat for ~ five months and pulled out when they began to assemble engines for '72.