NOS LT-1 Fuel Pump

[Kevin G.]

Last night I purchased an NOS fuel pump for my 72LT-1 on *bay. The cost was about the same as the Paragon "correct" reproduction. My first question, does the following information help determine when the pump was produced? Second, best guess at what length of life should I expect to receive from this pump?

"The item you are bidding on is a New Old Stock never installed original GM AC fuel pump that fits 1970-72 Corvettes with LT1-350 and special high performance 350 cid v8. It is still in the AC box and has "40709" stamped into the lip and "AC" stamped into both sides.It has been stored indoors all it's life in a dry climate controlled building.

Part # 6470110 Group # 3.900"

Regards,

[Joe L.]

Re: NOS LT-1 Fuel Pump

Last night I purchased an NOS fuel pump for my 72LT-1 on *bay. The cost was about the same as the Paragon "correct" reproduction. My first question, does the following information help determine when the pump was produced? Second, best guess at what length of life should I expect to receive from this pump?

"The item you are bidding on is a New Old Stock never installed original GM AC fuel pump that fits 1970-72 Corvettes with LT1-350 and special high performance 350 cid v8. It is still in the AC box and has "40709" stamped into the lip and "AC" stamped into both sides.It has been stored indoors all it's life in a dry climate controlled building.

Part # 6470110 Group # 3.900"

Regards,

Kevin------


There may be a date on one of the flaps of the box. Also, there should be a date code as part of the AC type number stamped onto the flange of the pump. Unfortunately, I have forgotten how to decode these fuel pump date codes.

Otherwise, all that could be said about it is that it was manufactured sometime between 1970 and about 1984 when AC ceased the manufacture of mechanical type fuel pumps.

How long will it last? That would be anyone's guess. I would say that the elastomeric internal components should be in pretty good shape even though it may be old. However, the compatibility of those components with modern-day fuel might be less than ideal.

[Jeff B.]

Re: NOS LT-1 Fuel Pump

Kevin,

Attached is a photo of the stamp on my original 40956 fuel pump. I'm not sure how to read the date code which I am assuming is 229K (the first four digits). My 1972 LT-1 was built on June 26th, 1972. Hope this helps.

Jeff

[Kevin G.]

Re: NOS LT-1 Fuel Pump

Kevin------


There may be a date on one of the flaps of the box. Also, there should be a date code as part of the AC type number stamped onto the flange of the pump. Unfortunately, I have forgotten how to decode these fuel pump date codes.

Otherwise, all that could be said about it is that it was manufactured sometime between 1970 and about 1984 when AC ceased the manufacture of mechanical type fuel pumps.

How long will it last? That would be anyone's guess. I would say that the elastomeric internal components should be in pretty good shape even though it may be old. However, the compatibility of those components with modern-day fuel might be less than ideal.

Joe, My thought was that the group number might narrow the manufacture date down somewhat. From the picture on the listing the pump does have the code on the flange, however too small to be read. I'll have to wait until it arrives to attempt to decipher it. Lets see if there is a date on the box, that can be compared to the code on the flange.
I do realize that guessing the longevity of it is exactly that, a guess. Of course I don't plan on driving the car to often, I'll keep my fingers crossed and hope for the best.
As always thank you!

Kevin,

Attached is a photo of the stamp on my original 40956 fuel pump. I'm not sure how to read the date code which I am assuming is 229K (the first four digits). My 1972 LT-1 was built on June 26th, 1972. Hope this helps.

Jeff

Jeff,

There was a great thread on deciphering these codes sometime back. If I remember correctly there are still some questions as to exactly how to read them. The original pump on my LT-1 recently failed and I have a reproduction on the car now. I have been searching for an NOS pump and was lucky to come up with the one I found. I'll follow up on the code when I receive it.

Thanks for your information! Nice picture too!

Regards,

[Ronald L.]

Re: NOS LT-1 Fuel Pump

We did not get to a conclusive means of identifying the MFG date for the C2's, I think by 1970 the coding was a little clearer, as this is when the 4-digit date coding was though to start, but not completely conclusive.

There will be a date on one of the bottom box flaps, if in 1970 it most likely will be two numbers and then a circular set of numbers that "could be" from 1 - 12, for other AC Division parts, look for more on this dating ina future thread.

The data off this box could help us decipher what the date coding actually means.

And Jeff,

the 229K, hard ot tie this to a car made June 26, which was no more that day=180, of any year, so the code has to be different.

If K was the year, 1972, 229th day would be a date after the car was produced.
If K= 1971 then you'd have in excess of 6 months to when the part was installed.


Could the code follow this theory(?):

A=Sep
B=OCT
C=NOV
D=Dec
E=Jan
F=FEB
G=Mar
H=Apr
J=May
K=Jun
L=Jul

Even this theory does not work for that dated part on your original car.

I think 2-29 means Month/Day and the letter has to do with the mfg line or plant up in Flint MI.


Here is the original thread on fuel pump date codes...
https://www.forums.ncrs.org/showthread.php?t=75895

[Joe L.]

Re: NOS LT-1 Fuel Pump

Joe, My thought was that the group number might narrow the manufacture date down somewhat.




Regards,

Kevin------


The parts group number, 3.900 in this case, has absolutely no relationship whatsoever to the manufacture date of a part.

[Jack H.]

Re: NOS LT-1 Fuel Pump

On life expectancy, I bought two of Paragon's "Last of the Mohicans" AC base car pumps for my '71. One is installed and has logged +60K miles without a hiccup for ten years now. The other sits 'patiently' on the shelf (NOT for sale)...

[Joe C.]

Re: NOS LT-1 Fuel Pump

Kevin,

Try this link:

https://www.forums.ncrs.org/showthre...75895&uid=9469

Should be helpful.

[Ronald L.]

Re: NOS LT-1 Fuel Pump

These pumps are being rebuilt in California, the tools and prints are out there.

Basically they use all new internal pieces with the die cast piece that has the AC cast logo and part number stamping being reused. That is what the Big Box stores are selling.

[Greg Y.]

Re: NOS LT-1 Fuel Pump

I looked on a website selling the rebuilt AC fuel pumps and they list a 40956 pump as correct for the 72 LT1, however, I looked in the corvette parts and accessories catalog from Chevrolet and it calls for the 40709 and states it is for years 69-72. Any information on this?

[Kevin G.]

Re: NOS LT-1 Fuel Pump

My findings....................
Front of Box

Top of Box

Flange Code 282F40956

Inside Top Flap of Box

Bottom of Box

[Dave S.]

Re: NOS LT-1 Fuel Pump

Kevin,
That appears to be a 1989 box and likely a 1989 fuel pump. Nice useable NOS pump but likely has some differences in the casting, stampings and external detail from a 1972 pump.

[Joe C.]

Re: NOS LT-1 Fuel Pump

Clock on inside top flap of box: 10/89 = Oct 1989

Top of Box Code: 0002J9 = 2nd week, October, 1989

Flange Code: 282F = 282nd day (non leap year) = October 9th

Therefore, the character "F" would represent "October" in 1989.

[Joe L.]

Re: NOS LT-1 Fuel Pump

My findings....................
Front of Box

Top of Box

Flange Code 282F40956

Inside Top Flap of Box

Bottom of Box

Kevin------

The AC type 40956 was actually used in PRODUCTION on 1972 LT-1's. How it differs from the type 40709 I've forgotten. Obviously, though, the differences must be minor since this 40956 was boxed and labeled as a 40709.

Does this pump have the "AC" logo on the sides of the casting?

[Terry M.]

Re: NOS LT-1 Fuel Pump

One of the more visible differences is the angle of the fuel inlet fitting. We detail that difference in the TIM&JG.