Large port front head

[41craig]

I'm starting to rebuild a 1942 EL that I bought 35 years ago. I broke down the motor and it has sat like that ever since. I noticed that the front head has no date plate on it. I have not seen this covered and wonder what year it is? This motor was on a chopper that I sold the rolling chassis and kept the motor and trans, The rear head is a '46.
Thanks, Craig