3919842 aluminum heads cast date missing?

[RALLY]

anyone know why a casting date could be missing from one of my heads? its not ground off at all, its just not there. the other head has a cast date of 3-16-69, but the other has nothing. anybody have an answer to my questions, can you help?

[VintageMusclecar]

I had a pair of them like that years ago. They were 1980's units purchased over the counter by a local racer.

No idea why there were no dates. http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

Eric