Fuel pump date code? David Liukkonen

[Jack H.]

Re: Fuel pump date code? David Liukkonen

You hit that one on the nose (date code of casting in the recess of the 'blind' hole that wasn't drilled/tapped on early 4656/4657 pumpd), but that's not the subject of this thread. The thread is about the 'extra' alpha characters that were STAMPED on the mounting flange along with the PN designator of various AC pumps, their significance, Etc.

[Paul B.]

Re: Fuel pump date code? David Liukkonen

David, just looked at my '68 Bowtie car's pump that was judged to be original in 2004 at Windsor. Had to replace it this past summer. It is off a 46,000mi '68 L-79/4spd coupe. Looks just as "aged" and original as the other engine pieces. Was judged to be original at several Regionals and a couple of Chapter Meets. Has the embossed "AC" on both sides of the vertical face. Anyways the stamped number on the flange that bolts to the block is as reads with NO SPACES is "282F40956" It is off a March 19, 1968 build '68 Coupe #14222. Appears like it had never been changed or off of the car before I had to remove it. Never could figure out the date coding.

[John H.]

Re: Fuel pump date code? David Liukkonen

The AC (replacement) on my '67 300hp which I just replaced has "143H40503" stamped on the forward flange.

[Gerard F.]

Re: Fuel pump date code? David Liukkonen

The AC (replacement) on my '67 300hp which I just replaced has "143H40503" stamped on the forward flange.

I, for one, am convinced that David is correct in his theory of date coding of C2 fuel pumps. This original (refurbed) 40433 from my late June 327/300HP has the FG (June 67) date code:



Just about everything on my 67 engine and drivetrain is dated within two weeks in June 1967. The FG fits like a glove.

Thank you David for your research.

[Tom F.]

Re: Fuel pump date code? David Liukkonen

Gentlemen:

AC Delco has a web site with a catalog lookup that I suggest you explore.

In looking up the following application 1967 to 1969 V/8 427 CID 7.0L 4BBL. Part number 40482 came up.

In 1967 it showed a VIN identification of IL, IM, IQ, IR.

In 1968 it showed a VIN identification of IL, IQ

In 1969 it showed a VIN identification of LM, LL

Could this be the the letters that appear as the prefix in front of the part number?

[Chuck S.]

Re: Fuel pump date code? David Liukkonen

Gentlemen:

AC Delco has a web site with a catalog lookup that I suggest you explore.

In looking up the following application 1967 to 1969 V/8 427 CID 7.0L 4BBL. Part number 40482 came up.

In 1967 it showed a VIN identification of IL, IM, IQ, IR.

In 1968 it showed a VIN identification of IL, IQ

In 1969 it showed a VIN identification of LM, LL

Could this be the the letters that appear as the prefix in front of the part number?

Doubtful. Those letters you show from the AC Delco site are actually the engine suffix that identifies the engine option using the fuel pump. In Terry's case, those letters in front of the part number do not compute as an engine suffix. In 70, the engine suffix went to three letters and Terry's LT1 suffix would be CTU. Even if it were a late 69 fuel pump, there is no LH suffix for 69 (Corvette) engines...I can't say for other Chevrolet engines.

[Terry M.]

Re: Fuel pump date code? David Liukkonen

You would have to look up 40709 to see the LT1, Holley application. For 1970 the engine code would have been CTU (early) and CTK (later).

[David L.]

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.

John,
The cast date code (2-digit year with radial line segments for the months) inside the untapped hole on the 4657 and other fuel pumps of the era is very old news. I discovered this when I bought my first 4657 fuel pump in 1979. That date code is quite obvious. I am saying that the STAMPED date coding on AC fuel pumps on the flange began in 1965.
Dave

[Kevin G.]

Re: Fuel pump date code? David Liukkonen

Can you decipher this one for me please?

Thanks,

Kevin

[David L.]

Re: Fuel pump date code? David Liukkonen

Can you decipher this one for me please?

Thanks,

Kevin

Kevin,

I believe the code ("219K40956") may be either the 219th day of 1971 or the 219th day of 1969. Do you know the original car it came from?

Using the "2-letter code system" as seen on my 4657 pumps the second letter is the year (examples: E=1965, F=1966, G=1967, H=1968, I=1969).

Using the "3-numbers & 1-letter system" I believe the following:
P=1974, Q=1975, R=1976, ......................Z=1984.

The two systems do not seem to blend in together as there seems to be a two year discrepancy which has me somewhat confused. As I said before this is my date coding theory and I'm still working on it. With more examples maybe we can all come to some kind of conclusion.

Dave

[Kevin G.]

Re: Fuel pump date code? David Liukkonen

Kevin,

I believe the code ("219K40956") may be either the 219th day of 1971 or the 219th day of 1969. Do you know the original car it came from?

Using the "2-letter code system" as seen on my 4657 pumps the second letter is the year (examples: E=1965, F=1966, G=1967, H=1968, I=1969).

Using the "3-numbers & 1-letter system" I believe the following:
P=1974, Q=1975, R=1976, ......................Z=1984.

The two systems do not seem to blend in together as there seems to be a two year discrepancy which has me somewhat confused. As I said before this is my date coding theory and I'm still working on it. With more examples maybe we can all come to some kind of conclusion.

Dave

Dave,
Thank you!
This is the original fuel pump on my May 10th 72 coupe.

Keep up the good work, hope this helps.

Kevin

[Mike E.]

Re: Fuel pump date code? David Liukkonen

I have 3 original 71 LT-1 fuel pumps--from a 30k mile 2-star car (paint didn't make it) and two other cars that have not been messed with. One as early as 2485, another as late as 21653. All have exactly the same stamping as the one Terry shows: LH 40709 I am a firm believer that the LH is NOT a dating indicator stamping.

[David 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

[David L.]

Re: Fuel pump date code? David Liukkonen

I have 3 original 71 LT-1 fuel pumps--from a 30k mile 2-star car (paint didn't make it) and two other cars that have not been messed with. One as early as 2485, another as late as 21653. All have exactly the same stamping as the one Terry shows: LH 40709 I am a firm believer that the LH is NOT a dating indicator stamping.

Mike,

You are certainly entiltled to your opinion. How many other 1965 & newer AC fuel pumps have you studied in the past 20 years? 10?, 25?, 50?

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

I have a 40248 65 396 pump that was on the car since 74 I believe as a re-built unit, it has no number? A B or perhaps an 8. see pic attached...

A 40366 66 427 pump I have has 9H40366.

Any ideas???

I think I have to find that guy I went to grad school with that worked up there...