AC fuel pump date code research data

[Paul B.]

Re: AC fuel pump date code research data

I just checked an NOS AC pump I've had for years that is in it's original box. Original red A/C logo ball on box, box flap dated 7-75. Has 40769 in larger numbers, then 6470308 in smaller numbers after it. Pump is a long can style pump(bought as a spare for my '74 L-48 coupe), has A/C logo on both sides of pump arm housing. Pump has 260 P 40769 on the flange. The zero in 260 is slightly heavier than the "26". The "P" is about 10% larger than the numerical characters and it too is a "heavier, deeper" stamp.

If

K='71
L='72
M='73
N='74
O='75
P='76(or P for 1975 if letter O skipped for this year?)

...might not work for this pump, UNLESS the letter O was purposefully skipped due to being confused with a zero for the year 1975??? My '74 still has it's original pump on it, can't see it right now due to storage.

[David L.]

Re: AC fuel pump date code research data

Paul,

I read the date code on your "260 P 40769" AC fuel pump as the 260th day of 1976 (Sept. 16, 1976). The "7-75" (July 1975) AC box was probably stored in a warehouse for a year with a lot of other flattened AC boxes.

For my 1970 Camaro SS350 project I need a "DJ 40777" or "EJ40777" (April or May 1970) AC fuel pump but all that I have is a NOS "263 K 40777" AC fuel pump (263 day of 1971, or Sept 20. 1971) without a box as well as a "058 T 40777" AC fuel pump (58th day of 1980) in a box dated Aug. 1977.

Apparently the AC fuel pump date coding format changed in 1971.

Dave

[Brian G.]

Re: AC fuel pump date code research data

I believe this is the original pump on the wife's January built '75...........

Fuel Pump 3.jpg

[David L.]

Re: AC fuel pump date code research data

I believe this is the original pump on the wife's January built '75...........

[ATTACH=CONFIG]43676[/ATTACH]

Brian,

Is your wife the original owner? I would say the "236 R 40769" pump is dated the 236th day of 1978 (Aug. 24, 1978) but that is just my opinion.

Dave

[Timothy B.]

Re: AC fuel pump date code research data

David,

I wanted to add to your information about fuel pump date codes. I just aquired a 40433 fuel pump for my 67 that has a date code stamping of LF40433. The pump has a 66 that's cast just inside the lever area so I think the date would be December 66.

The pump has been rebuilt by goat hill and looks very nice, after I install it and check the pressure I will let you know how it performs.

[David L.]

Re: AC fuel pump date code research data

David,

I wanted to add to your information about fuel pump date codes. I just aquired a 40433 fuel pump for my 67 that has a date code stamping of LF40433. The pump has a 66 that's cast just inside the lever area so I think the date would be December 66.

The pump has been rebuilt by goat hill and looks very nice, after I install it and check the pressure I will let you know how it performs.

I agree.

Dave

[Loren L.]

Re: AC fuel pump date code research data

So, after agreeing with me that my 40083 pump without a suffix (or a prefix) and internally dated April
1965, is original, is it now your contention that ORIGINAL AND SERVICE REPLACEMENT fuel pumps after "time X" are ALL suffixed or prefixed for ID - or is it only service replacements?

[Jeffrey S.]

Re: AC fuel pump date code research data

David,
I found a fuel pump that was installed in my early '69 as a replacement sometime around 1972. I removed it in the 90's and put a new one on basically for cosmetic reasons. It is stamped 7L40956. The flange is somewhat pitted in this area but there doesn't appear to be any other numbers or letters stamped in this area. Does this make any sense?
Jeff

[David L.]

Re: AC fuel pump date code research data

So, after agreeing with me that my 40083 pump without a suffix (or a prefix) and internally dated April
1965, is original, is it now your contention that ORIGINAL AND SERVICE REPLACEMENT fuel pumps after "time X" are ALL suffixed or prefixed for ID - or is it only service replacements?

Loren,

I started this same thread on the Nasty.Z28 website back in Feb. 2011. The link below might help answer your question. My date code theory is still only a theory and is not recognized by any organization and probably never will be recognized.

Dave

http://www.nastyz28.com/forum/showthread.php?t=207770

[David L.]

Re: AC fuel pump date code research data

Jeff,

I believe that your "7L40956" pump is dated the 7th day of 1972. Refer to the link below.

Dave

http://www.nastyz28.com/forum/showthread.php?t=207770

[Terry M.]

Re: AC fuel pump date code research data

Dave,

Why have you related the pump date to the engine assembly date? In the case of Corvettes, and I would bet Camaros as well, the fuel pump was installed at the vehicle assembly plant. It would be more accurate to reference the fuel pump date to the vehicle assembly date IMO.

Mine seems not to fit your theory. Attached is the best photo I have of the fuel pump. I know it is small, but it is all I can do. It is probably the one I posted int eh past. It is possible my date is LN rather than the LH that you have in your chart. Body built is January 29 (A29).

Right side up.png

[David L.]

Re: AC fuel pump date code research data

Dave,

Why have you related the pump date to the engine assembly date? In the case of Corvettes, and I would bet Camaros as well, the fuel pump was installed at the vehicle assembly plant. It would be more accurate to reference the fuel pump date to the vehicle assembly date IMO.

Mine seems not to fit your theory. Attached is the best photo I have of the fuel pump. I know it is small, but it is all I can do. It is probably the one I posted int eh past. It is possible my date is LN rather than the LH that you have in your chart. Body built is January 29 (A29).

[ATTACH=CONFIG]43747[/ATTACH]

Terry,

You are correct. The fuel pump date code would be related to the body build date since the pump was installed on the assembly line and not at the engine plant.

I have no answer for your "LN40709" (or "LH40709") fuel pump. I assume you are the original owner of your 1970 LT1 and that is the original pump.

I started this thread back in Feb. 2011 after studying AC fuel pump stampings for many years and noticing a pattern. I do not have all the answers and probably never will. I did this study for myself and anyone else that was willing to listen and make comments. I am 100% convinced about the date codes. Date coding does make sense as many other GM parts are date coded for quality control purposes. Many others refuse to acknowledge the date codes, particularly those who sell original AC fuel pumps as it really limits the potential buyers, and that is fine with me. In general, my goal to to find out which parts are original assembly line parts. I could care less about car shows, the point system, and what is acceptable in the judging.

BTW, the date coding of GM bumper jacks & scissor jacks stated in 1967. One vender (RH INC.) that made jacks for the Ford Motor Co. started date coding their bumper jacks a few years earlier.

AC fuel pump date coding is currently only a theory, nothing more, nothing less.

Dave

[Terry M.]

Re: AC fuel pump date code research data

Terry,

You are correct. The fuel pump date code would be related to the body build date since the pump was installed on the assembly line and not at the engine plant.

I have no answer for your "LN40709" (or "LH40709") fuel pump. I assume you are the original owner of your 1970 LT1 and that is the original pump.

I started this thread back in Feb. 2011 after studying AC fuel pump stampings for many years and noticing a pattern. I do not have all the answers and probably never will. I did this study for myself and anyone else that was willing to listen and make comments. I am 100% convinced about the date codes. Date coding does make sense as many other GM parts are date coded for quality control purposes. Many others refuse to acknowledge the date codes, particularly those who sell original AC fuel pumps as it really limits the potential buyers, and that is fine with me. In general, my goal to to find out which parts are original assembly line parts. I could care less about car shows, the point system, and what is acceptable in the judging.

BTW, the date coding of GM bumper jacks & scissor jacks stated in 1967. One vender (RH INC.) that made jacks for the Ford Motor Co. started date coding their bumper jacks a few years earlier.

AC fuel pump date coding is currently only a theory, nothing more, nothing less.

Dave

Yes, Dave that is the pump originally installed on my 1970 LT1 and I was the first to take it off when it began to leak in the mid 1980s.

I can understand a vendor's motivation in not acknowledging the existence of date codes. I can also understand the reluctance of judging organizations because it is unlikely we will ever have the time and facilities to judge fuel pump stamps when judging Corvettes, or probably Camaros or any other model line either. On the other hand we have included more and more information in the NCRS judging manuals that are for the benefit of restorers, so maybe this is another of those items. Just some things that make one go HMMM.

[David L.]

Re: AC fuel pump date code research data

Terry,

I just got an email from someone on the NastyZ28 forum who has a "LH40709" AC fuel pump from a 1970 Corvette LT1.
"LH" would be Dec. 1968 in my theoretical AC fuel pump date coding. Like I said before, I do not have all the answers, just passing on information.

Dave

[Jeffrey S.]

Re: AC fuel pump date code research data

Dave,
Thanks for the response. I thought that it was that date but I also thought that it would be "007" rather than just "7".
Jeff