Fuel pump date code? David Liukkonen

[David L.]

Re: Fuel pump date code? David Liukkonen

The date code system changed about that time. I think your fuel pump ("8K40709") may be dated the 8th day of 1971. I am currently on the Cape so I do not have my research with me. There are usually 3 numbers before the letter but it is understandable that they would not stamp it "008K". I'll check when I get home.

[Dave S.]

Re: Fuel pump date code? David Liukkonen

The date code system changed about that time. I think your fuel pump ("8K40709") may be dated the 8th day of 1971. I am currently on the Cape so I do not have my research with me. There are usually 3 numbers before the letter but it is understandable that they would not stamp it "008K". I'll check when I get home.

David,
If you are on Cape Cod then I'm a neighbor of yours - Brewster. The pump in the photos came off my 21K mile car. After a long storage from 1986-1999, when I bought the car from the original owner, this fuel pump started leaking. I cannot say for sure its original but I'm 99% sure it is. I've got a 70 with an original fuel pump that is buried in my garage but once spring arrives I'll get that stamping for you.

[Don L.]

Re: Fuel pump date code? David Liukkonen

Kevin,

Your ORIGINAL 1972 Corvette (May 10, 1972) fuel pump stamped "219K40956" (where I believe "219K" = the 219th day of 1971 or August 7, 1971) seems to fit in with my fuel pump date coding theory where E=1965, F=1966................and K=1971. Somewhere between 1969 and 1971 the AC fuel pump date code system changed from the 2-letter date code to the 3-number & 1-letter date code. Thanks for your input.

Dave

What a great thread! Thanks Terry for kicking this one off. Lots for me to learn and it sounds like some new ground for others of us too. I LOVE these forensic topics the most!

David, per your direction above, "E" = 1965. Was there an AC part number 40769 in 1965?

This thread piqued my interest and I took a look at mine. I'm trying to decipher my pump and it looks to read 153E40769. For my car (Aug '71 built base eng.), the julian 153 lines up fairly well. The "E", if 1965 only, certainly doesn't work. I could have it all wrong. I will clean it up, get a better look, and hopefully post a picture.

[David L.]

Re: Fuel pump date code? David Liukkonen

What a great thread! Thanks Terry for kicking this one off. Lots for me to learn and it sounds like some new ground for others of us too. I LOVE these forensic topics the most!

David, per your direction above, "E" = 1965. Was there an AC part number 40769 in 1965?

This thread piqued my interest and I took a look at mine. I'm trying to decipher my pump and it looks to read 153E40769. For my car (Aug '71 built base eng.), the julian 153 lines up fairly well. The "E", if 1965 only, certainly doesn't work. I could have it all wrong. I will clean it up, get a better look, and hopefully post a picture.

Don,
The 40769 pump (GM # 6470308) did not exist in 1965. It was first issued on the 1970 models. I believe that your pump MAY be a replacement and the "153E" on your pump MAY be the 153rd day of 1991. You could still buy the 6470308 pump (AC 40769) over the counter in March 1991 for $33.80 as per my GM Price Schedule (Mar. 1991).
I believe "Z" = 1986 and the letters start again where "A" = 1987, etc. It's just my theory, not a proven fact.

Dave

[David L.]

Re: Fuel pump date code? David Liukkonen

David,
If you are on Cape Cod then I'm a neighbor of yours - Brewster. The pump in the photos came off my 21K mile car. After a long storage from 1986-1999, when I bought the car from the original owner, this fuel pump started leaking. I cannot say for sure its original but I'm 99% sure it is. I've got a 70 with an original fuel pump that is buried in my garage but once spring arrives I'll get that stamping for you.

Dave,

I do not live on the Cape but I visit the Cape 4 or 5 times each year. I would be very interested in finding out the stamping on your original 1970 fuel pump.

Dave

[Dave S.]

Re: Fuel pump date code? David Liukkonen

Dave,

I do not live on the Cape but I visit the Cape 4 or 5 times each year. I would be very interested in finding out the stamping on your original 1970 fuel pump.

Dave

Dave,
I do not have a photo of the stamping but did go back to my notes from 1998 when I bought the car. LH40709 is what I have written down. I will re-check later in the spring but I'm sure it is correct. This car is a later build (#14803) with an engine stamping of V0702CTK.

[Don L.]

Re: Fuel pump date code? David Liukkonen

Thanks much. This does make sense, as 1991-1992 was when the body off was done on my car. Looks like it was easier for the previous owner/restorer to replace vs rebuild .

Other than the date, should I expect any discernable differences between a June 1971 part number AC 40769 and a June 1991 example of the same part number?

A great learning for me on this thread. Thanks to all for contributing.

...and I was thinking I was running our of projects!

[David L.]

Re: Fuel pump date code? David Liukkonen

Don,
Is there an "AC" casting on your "153E40769" fuel pump? I believe that the AC fuel pumps made in recent years do have have the "AC" casting.
Dave

[Don L.]

Re: Fuel pump date code? David Liukkonen

Although not yet sure as to the accuracy of the date stamp, I am certain that the "AC" is on the casting.

I seem to recall some discussion about a different length to the body on some generations vs others. Anything to that?

Thanks.

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

Don,

If you can, contac the guy that did the body off and see if he remembers what he did. Perhaps a receipt? The AC tools were purchased with prints many years ago. THe guy could have ahd the unit rebuilt.

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

David,

Focusing on two digit codes, prior to 1971...

How or what are the second digits you have noted:
H, F, G, K? Any others?

Why wouldn't the code be:

A-Aug
B-Sep
H-Mar
J-May
K-Jun
L-Jul

How do we expalin a mix of letters and numbers on the first digit?

[David L.]

Re: Fuel pump date code? David Liukkonen

This is what I have found for the first letter:
A = Jan.
B = Feb.
C = Mar.
etc...............
J = Oct.
K = Nov.
L = Dec.

This is what I have found for the second letter:
E = 1965
F = 1966
G = 1967
H = 1968
I = 1969
J = 1970
etc................

The letter "I" was used. In most STAMPED date code systems the letter "I" is generally NOT used. AC fuel pumps were not date coded before 1965 as far as I know.

I do not really understand your letter codes for the month. The dates on any parts had nothing to do with the first month of production on the assembly line if that is where you are going. The first month of production was NOT always August. Date codes were used for quality control.

I can not explain why numbers replaced the first letter. Maybe different AC plants changed the date code system at a different time. Maybe some day we will find out, maybe never.

Dave

[Chris E.]

Re: Fuel pump date code? David Liukkonen

David, your idea of date coding seems to hold up with my fuel pump.

When I took the car apart 3 years ago, it had 77K miles on it. My family has owned it since 1973 and I have my dad's hand written service record on the car from roughly 35K miles to current. I believe the fuel pump is original to the car, as there were so FEW non-original parts on the car.

Here's a picture. I have others if you need to see more detail, but I figured the stamping would be enough. My casting number 40433 agrees with Gerald's posted earlier. And the "FF" date would decode to June of 66. My VIN is #183, so I have a LOT of Aug 66 parts on the car.

[Dale C.]

Re: Fuel pump date code? David Liukkonen


Dale

[David L.]

Re: Fuel pump date code? David Liukkonen

Chris,

The June 1966 ("FF") fuel pump date matches up very well with your early 1967 with #183 V.I.N. (August 1966). The 40433 pump was used on early 1967's and the 40503 pump was used on late 1967's. Your 40433 pump is definitely original since the 40433 pump was discontinued sometime in the middle of 1967 production.

I recently found a "6942 LE" (where "LE" = Dec. 1965) fuel pump in my garage attic that I bought at a junk yard in Wilton, NH on 4/11/89 from an early 1966 Chevrolet w/283 engine stamped "T1222GA" (Dec. 22, 1965).

Dave