NOS XK120 head... date of manufacture?

quite common____________
terry

I guess perhaps early heads without a serial number stamp are rare. Jag-ur has one, Welsh has one, and I have one. Mine is not NOS, it is used.
PICT0002

I see the one at Welsh also is stamped with a number 1 for the hyphen in the part number. Funny that it appears that the old number was ground off, and the 6 is smaller than the 733. Did the William Mills foundry cast some with the wrong number? Could be I suppose if they were making other heads using the same cope and drag but different cores and forgot to change the part number on the pattern one day. Sure is filthy for being NOS. If they expect stratospheric money they should clean it.

Its production sequence number seems to be 163A. This is opposite of the PS numbers I have seen with the letter(s) before the numerals. I wonder if Jag-ur’s could be 11A rather than 114? Do you want to remove that paint and see if there is a letter or two under there?

We haven’t figured out what would be the difference between a C6733 and a C6733/1 yet. It could be an improvement in the cooling passages or it could be something as trivial as adding the letter A and the plinth at the rear for the number to be stamped. That would mean a change on the molding pattern.

But we have already established that a C6733/1 is not correct original for a 120, though it would be fine for if you want to fake matching numbers on a Mark 1.

I’ll take some paint remover to it over the weekend and see. I wondered the same thing…