Fuel pump date code? David Liukkonen

[Terry M.]

David Liukkonen,

Any thoughts on the date code on this fuel pump from my 1970 LT1? LH 40708

[David L.]

Re: Fuel pump date code? David Liukkonen

Terry,

Were you a baseball pitcher? You just threw me a curve ball.
First of all, I believe the number should be "40709" as I read it in your photo. Are you sure it is "LH 40709"? Could it possibly be "IH 40709" or "1H 40709"? Try cleaning it up a little. Sometime in the early 1970's the code changed to 3 numbers plus 1 letter before the AC part number (example: "154P 40727", dated 154th day of 1974, I believe).

My 1969 Corvette Parts Catalog (Sept. 69) shows GM # 6470110 (type 40709) for the 69 Corvette w/SHP 350. My 1972 catalog shows the same numbers for 69-72 Corvette w/SHP 350. The "LH" part does not fit in with my theory. I guess it's back to the drawing boards. What is the engine assembly date on your 70 LT1? I would like to add this information to my survey. Are you sure that the pump was original equipment?

Dave

[Terry M.]

Re: Fuel pump date code? David Liukkonen

Terry,

Were you a baseball pitcher? You just threw me a curve ball.
First of all, I believe the number should be "40709" as I read it in your photo. Are you sure it is "LH 40709"? Could it possibly be "IH 40709" or "1H 40709"? Try cleaning it up a little. Sometime in the early 1970's the code changed to 3 numbers plus 1 letter before the AC part number (example: "154P 40727", dated 154th day of 1974, I believe).

My 1969 Corvette Parts Catalog (Sept. 69) shows GM # 6470110 (type 40709) for the 69 Corvette w/SHP 350. My 1972 catalog shows the same numbers for 69-72 Corvette w/SHP 350. The "LH" part does not fit in with my theory. I guess it's back to the drawing boards. What is the engine assembly date on your 70 LT1? I would like to add this information to my survey. Are you sure that the pump was original equipment?

Dave

I was quoting what I thought I saw for numbers and letters in this photo. I'll clean up the fuel pump and see what I can find.

The engine assembly date is V0114CTU (January 14, 1970) Since the fuel pump was installed on the engine at St Louis the body build date of A29 (January 29, 1970) might be more significant.

I bought the car new, so I am as sure as I can be that this is the original fuel pump installed at St. Louis.

I don't play ball, and was among the last chosen when we picked teams in high school. Athletics are not, and never were, my interest.

[Gerard F.]

Re: Fuel pump date code? David Liukkonen

Terry,

Were you a baseball pitcher? You just threw me a curve ball.
First of all, I believe the number should be "40709" as I read it in your photo. Are you sure it is "LH 40709"? Could it possibly be "IH 40709" or "1H 40709"? Try cleaning it up a little. Sometime in the early 1970's the code changed to 3 numbers plus 1 letter before the AC part number (example: "154P 40727", dated 154th day of 1974, I believe).

My 1969 Corvette Parts Catalog (Sept. 69) shows GM # 6470110 (type 40709) for the 69 Corvette w/SHP 350. My 1972 catalog shows the same numbers for 69-72 Corvette w/SHP 350. The "LH" part does not fit in with my theory. I guess it's back to the drawing boards. What is the engine assembly date on your 70 LT1? I would like to add this information to my survey. Are you sure that the pump was original equipment?

Dave

Dave,

By your theory, wouldn't "LH" be December 68 for a 1969 car? Maybe a little early for Terry's 70 LT1, but possible if they used the same fuel pump.

Just a thought.

[David L.]

Re: Fuel pump date code?

Jerry,

The "LH" code would be November ("L") 1968 ("H") according to my date coding theory since I have seen the letter "I" used in these codes (example" "DI 40657", where "DI" would be April 1969 from a NOS pump , GM #6417337 discontinued August 1971, for 1968-1969 Corvettes with 327 & 350 base engines). Most vendors that stamped date codes did not normally use the letter "I".

The Nov. 1968 ("LH") date would be about a year too early for a Jan. 1970 car but I guess it is possible but not probable. I hope to get more original AC pump codes from their original cars to either prove or disprove my theory but most non-rebuildable AC pumps that were replaced many years ago were also trashed.

Dave

[Chuck S.]

Re: Fuel pump date code?

Jerry,

The "LH" code would be November ("L") 1968 ("H") according to my date coding theory since I have seen the letter "I" used in these codes (example" "DI 40657", where "DI" would be April 1969 from a NOS pump , GM #6417337 discontinued August 1971, for 1968-1969 Corvettes with 327 & 350 base engines). Most vendors that stamped date codes did not normally use the letter "I".

The Nov. 1968 ("LH") date would be about a year too early for a Jan. 1970 car but I guess it is possible but not probable. I hope to get more original AC pump codes from their original cars to either prove or disprove my theory but most non-rebuildable AC pumps that were replaced many years ago were also trashed...

This thread is like dejuvu all over again. Three years ago, I couldn't even convince "more experienced" members that fuel pumps were even dated. I'm glad to see someone is making progress in that area.

https://www.forums.ncrs.org/showthre...+pump&uid=3043

Of course, I totally forfeited the debate when I revealed the subject was a Carter fuel pump...we all know that never happened...even if it did have a white crayon inspection mark on it.

[Harmon C.]

Re: Fuel pump date code?

I thought that number was the part number of the pump. It is close to the part number I think on pumps I have.

[David L.]

Re: Fuel pump date code? David Liukkonen

The 5 numbers are the AC part number but the 2 letters are not.

[Jack H.]

Re: Fuel pump date code? David Liukkonen

In the late C1 JG books, they distinguish 'original' vs. 'replacement' fuel pumps by both the size of ID stamping font as well as the presense/absence of 'prefix' designators. If memory serves, they attribute the prefix designators (generally alpha characters) as a form of production source ID coding...

[David L.]

Re: Fuel pump date code? David Liukkonen

Jack,

I have found in my research that AC fuel pumps made in 1964 and prior were NOT date coded. The additional 2 letters that were added to the stamped AC part number occurred in 1965. One of the reasons why vendors put date codes on their parts was for QUALITY CONTROL and that is why I believe that these letters indicate a date code.
I do NOT use any NCRS judging manuals in my research. It seems that once something is printed in these judging manual it is "cast in stone" and everyone believes it because the NCRS manuals can never wrong. I tend to be more open minded and do research based on studying actual parts and using documentation from that same era. Many "restorers" like to be told what parts are correct for their car by "experts" rather than do their own long term research because it's much easier and much cheaper. I strive for a standard much higher than the NCRS judging manuals.

Dave

[Tom F.]

Re: Fuel pump date code? David Liukkonen

Hello Dave:

I spoke with two friends who worked for fuel pump manufacturers and they said that AC didn't put date codes on their fuel pumps. They felt that the prefix letters that were on the pumps were the manufacturing plant identification.

[David L.]

Re: Fuel pump date code? David Liukkonen

Tom,
If that's the case then AC must have had hundreds of manufacturing plants. I still believe the pumps were date coded starting in 1965.
Dave

[Tom F.]

Re: Fuel pump date code? David Liukkonen

David:

The only thing that was confirmed was that all electric fuel pumps were date coded and still are. That's because of quality issues.

[Tom F.]

Re: Fuel pump date code? David Liukkonen

Hello David:

I think you may have broken the code. You mentioned that GM started using the letters on fuel pumps starting in 1965. Up until 1965 there were only small blocks. In 1965 they introduced the 396 CID and from that point on different engine sizes and performance packages. I believe that engine manufacturing took place at the Tonawnda, NY Mfg. plant. The two alpha letters in front of the part number were most like used in the assembly process for the engine type. Rather than looking at a four or five didgit part number. The letters changed as the years changed, Your thoughts and suggestions.

[John D.]

Re: Fuel pump date code? David Liukkonen

The 63 4657 fuel pump is definitely date coded. Other 4657 pumps are date coded also. My 63 has a NOV 62 dated 4657 pump. In my collection of pumps ALL of the 4657 pumps have a date code. I was recently looking at a 4657 dated 61.
We covered this about a year ago or so. Look at where the fitting goes on bottom castings. THen look at a round hole near this fitting. Inside the hole you will see the year of manufacture of the AC pump. The slash marks may indicate the month of production.
Once on the car you can't see the date code.