Can anyone identify this cylinder heads

[jakz]

Hello everyone, my 74 911s has a rebuilt engine with several upgrades that I can see without tearing into it, today I was looking for clues trying to figure out if the rebuild was made to stock specs and I found the casting numbers on the heads and after reading and searching everywhere I could I just couldn't find info on the numbers, I looked at the cylinder head cross reference post and it doesn't mention this ones, hoping anyone has any info it would be very much appreciated

Casting numbers
911.104.342.0R
Date 10-73 K1819s

[group911@aol.co]

The casting date would sure indicate heads from 1974

[jakz]

Thank you, it seems to be a stock rebuild then.

[E Sully]

Here's a chart for future reference.