Help with my head

[Old Ugly 40]

The heads on my 40 EL are in rough shape but I have a pretty good set of 41 heads.
Can I use the 40 rear rocker box on the 41 rear head?
Thank you in advance.
Rod
#25781

[Rubone]

Yes, you can....

[Old Ugly 40]

Thank you Rubone. You are the greatest.
I assumed that I could but needed to be sure.
Thanks again.
Rod

[Old Ugly 40]

Hi to all,
I took both heads off my 40 EL today and noticed something unusual, Neither head has a date code that I can see. Does anyone have the answer to this mistery?
Thank you for any input.

Rod
#25781

[Jerry Wieland]

Hi to all,
I took both heads off my 40 EL today and noticed something unusual, Neither head has a date code that I can see. Does anyone have the answer to this mistery?
Thank you for any input.

Rod
#25781

Every OEM 1940 EL that I have worked on does NOT have date codes. I believe it is supposed to be that way.

Jerry

[Old Ugly 40]

Jerry,
Thank you so much for your reply.
Very interesring. I assume [ bad thing to do ] the heads only did not have date codes as my rocker boxes have B 9 and D 9 date codes. Did 36 -39 EL heads have date codes?
It would be nice if more people with knowledge about this could chime in.
Thank you again.
Rod

[RichO]

Check your belly #'s and you'll find they are the only ones with just an E.

[Rubone]

Every OEM 1940 EL that I have worked on does NOT have date codes. I believe it is supposed to be that way.

Jerry

My guess is first year big port heads were made off a master mold, later productions were coded.

[Old Ugly 40]

Check your belly #'s and you'll find they are the only ones with just an E.

RichO,
Thank you for your input. Another 40 EL oddity.
Rod

[Old Ugly 40]

My guess is first year big port heads were made off a master mold, later productions were coded.

Rubone,
Once again, thank you for your knowledge and input.
This seems to be the most logical reason there were no date codes. But one has to think it would have been easier to track problems if they had used date codes.
God [H.D.] worked in mysterious ways.
Rod

[Old Ugly 40]

Hi all.
This, I hope, 20230318_140733.jpg is a picture of a crack in my 40EL front head. Also has a heli-coil, the nipple was very loose. After removeing the rivet was able to easily remove the nipple and easily thread it back in and tighten it but could not get it to seal. The seat area looks like it was repaired with solder. The rivet hole is also way to big (3/16"-1/4"). Also the exhaust port has a threaded 3/16" to 1/4" hole.
Ending this post now and will post rear head problems and questions later.
Thank you.
Rod

[Old Ugly 40]

Hi again.
Now rear head problems. 20230318_140535.jpg Crack in same area as front head and over sized rivet hole but not as bad as front head
When I presure tested this rivet leaked but the nipple was good. Tried to tighted the rivet with no luck. Tried makeing soft steel and aluminum rivets but couldn't get these to seal either. The exhaust port also has a taped hole.
Can these heads be repaired?
Thank you in advance for any advise.
Rod