I have what I believe is a 69 AC fuel pump. It has what appears to be "HH40669" stamped on the mounting flange of the pump. Can anyone decode this?
I believe your "HH40669" AC fuel pump is dated August (the 1st "H") 1968 (the 2nd "H"). I have done a lot of research about AC fuel pumps during the last 20 years. It all started years ago when I found a 1966 Chevrolet 327 engine ("T0521HAR", May 21, 1966 with roch. 4bbl.) in a junk yard which had all of it's original components (carb, starter, distributor, fuel pump, etc.) according to the stamped part numbers and date codes. I decoded the "4657EF" fuel pump to be May ("E") 1966 ("F").
My fuel pump date code theory is as follows:
The first letter is the month, A=Jan, "B"=Feb. ...........................L=Dec. (the letter "I" was used).
The second letter is the year, E=1965, F=1966, G=1967, H=1969.
NOTE: The AC pumps made in 1964 and prior do not have the 2 letter. I have an AC pump stamped only "4657" from a 1964.
Sometime in the early 1970's the date code changed to 3 numbers (the day of the year) and one letter (the year). I am still working ion this code.