1969 Z/28 40669 Fuel Pump - Correct Plating

[Edgemontvillage]

In the process of engine disassembly I removed the original 40669 crimped style fuel pump from my February 1969 dated DZ motor.  The fuel pump is dated AI or January 1969 and from the inlet threads it appears the crimp on bowl was originally gold cad plated. I am wondering if any original 40669 pumps were plated using silver cad/zinc? I have seen restored and NOS versions with gold or silver cad plated bowls however was silver cad ever used on original 40669 pumps in 1969?

Original 40669 AC Delco fuel pump (with 2 diaphragm weep holes)
 
Date code: AI or January 1969 - note inconsistent use of fonts in the number 6



Restored original 40669 fuel pumps  - gold cad and silver cad crimped on bowls.

[ZLP955]

Lloyd I have an original 40669 with the same January 1969 date code. I can't recall what the finish is, will dig it out and post some pictures within the next day or two.

[Edgemontvillage]

Lloyd I have an original 40669 with the same January 1969 date code. I can't recall what the finish is, will dig it out and post some pictures within the next day or two.

Thanks Tim, please do, I would also be interested in a photo of the stamp (date code), seems AC Delco used a variety of fonts in their stampings, I have seen no consistency even for 669 pumps produced in the same month (multiple production lines? plants?).

[ZLP955]

Lloyd I managed to find some older pictures of the pump saved on my laptop, can still retrieve it from storage if you want to see pictures of any other specific details.
This one seems to have used the same font style for both '6's in 40669, but interestingly the 'AI' has a double strike.

[Edgemontvillage]

Thanks Tim, here is another example of a restored 40669 with the same date code and double strike Month (A). Seems the media used during restoration has degraded the stamp. The font used for the "6"s is also the same.   

[RS_COPO_Canuck]

Interesting the different fonts on the 6.....rounded side and straight side

[Edgemontvillage]

Interesting the different fonts on the 6.....rounded side and straight side

The manufacturer's marks on the bottom of the casting are also different.

[ZLP955]

Lloyd I means to add with the above pictures that to my eye, the crimped base of the pump is gold, rather than silver - wondered if this answers your original question?

[Edgemontvillage]

Lloyd I means to add with the above pictures that to my eye, the crimped base of the pump is gold, rather than silver - wondered if this answers your original question?

Yes Tim, it does, I have also solicited information from a couple of experts who confirmed they have only seen gold cad /zinc plated fuel pump bowls on original 1969 Z/28s. Thanks for your help.

[Hans L]

Lloyd - as usual, great investigative work!    I checked the AC Fuel pump on my Z and it's a 40669 as well but I don't think it's original to the car - question though, how do you decode the date code?   

The code on mine is not that legible but none-the less, I have no idea how to decode it.  I did a search here and elsewhere and could not find any reference to decoding the fuel pump.    Appreciate any input on how to decode it.

Thanks,

Hans

[Edgemontvillage]

Lloyd - as usual, great investigative work! I checked the AC Fuel pump on my Z and it's a 40669 as well but I don't think it's original to the car - question though, how do you decode the date code?   

The code on mine is not that legible but none-the less, I have no idea how to decode it.  I did a search here and elsewhere and could not find any reference to decoding the fuel pump.    Appreciate any input on how to decode it.

Thanks,

Hans

Hans, thanks for the feedback. Based on my research original AC Fuel Pumps have two 1/8" vent/weep holes in the (AC logo'd) casting above the diaphram to vent fuel should the diaphram fail which are not found on service replacement or repro pumps. The date code and "40669" are stamped on the bottom/side profile of the cast base using 1/8" characters. The stampings are not consistent and the fonts used appear to vary somewhat (per the above). There are 2 threads on CRG dealing with decoding 40669 production dates which I found useful, below are the links:     

http://www.camaros.org/forum/index.php?topic=1170.0
http://www.camaros.org/forum/index.php?topic=12033.0

[68camaroz28]

Lloyd, sorry for the late reply but was overseas on vacation and followed some things but did not have my lap top and pictures to share. A couple years ago I purchased this fuel pump when Jere Stahl (RIP) was going out of business. I noted it was a correct number 40524 for our 68 Z/28 and wanted it for possible replacement if our re-built one goes bad. It’s dated July67 and wanted to show the yellow zinc bowl and how it would have looked on a car back in the day. Even a good look at what the gasket looked like. I was fortunate to obtain some neat things that he had accumulated and also where Chevrolet Engineering had sent him.

[ZLP955]

So is the correct plating gold cad or yellow zinc, or either?

[68camaroz28]

So is the correct plating gold cad or yellow zinc, or either?

Not sure Tim but JohnZ has mentioned many times prints called out both gold cad or yellow zinc was acceptable and yellow zinc was cheaper so that in reality was what was used more times than not. I would guess (assume) either is correct and how many people can really distinguish the differences in appearance?

[ZLP955]

OK, thanks Chick! I'm not restoring mine, just going to clean it up, but handy to know for the future.