Gas tank date codes

[x66 714]

If all my numbers are right but go backwards on the 9N569987 to 9N561885 is approxamately 2 weeks. So then about end 2nd or begining 3rd week December? That then puts it right on cowl production date of 12B. Then if my calculations of 18  69 which is 41/2 weeks comes out to Aug, Sept, Oct, Nov, 1/2 Dec  would fall roughly into my 12B build date. Don't know if I did my calculations right but looks like begining of 3rd week on vin? Now that I'm starting to slightly figure it out with everyones help it starts to make cense. Thanks all for excercising my brain. 

Lots to learn here. Keep reading & watching....Joe

[jdv69z]

So I have a 10B Oct 68 car. The code is front drivers side from what I'm reading, correct? Is it on the top of the flange, or the bottom looking from underneath. Is it visible with the tank in the car?

[firstgenaddict]

visible from under the car looking up at the corner.

[jdv69z]

Thanks, I'll check it out and add my data.

[jdv69z]

Ok, so here's my tank code: 8 69 10B Oct 68 build.

[cook_dw]

68 12D (Dec 67) LOS with 68 21

[Charley]

Early 09B 69 car. Dated 1 69

[KurtS]

The gas tanks are dated with a week and year code.
67 has a calendar week code. 16 D 7 would be the 16th week of 67, day shift. 40 6N would be 40th week of 66, night shift.
The format changed in 68 and 69 to have the week counted from the beginning of the *model* year. The extended 69 model year used tanks dated for the 70 model year.
LOS and NOR data is intermixed and shows the same pattern.

67:
11A  42 6D  (stamped 42 9D)
11A  40 6N
??    52 N 6
01B  52 N 6
02A   5 N 7
02B   5 D 7
02C   5 D 7
02E   6 D 7  (stamped 7D6)
03B   9 D 7
03C 11 N 7
03C 11 N 7
04B   4 N 7
04D   5 D
05A  17 D 7
05C  16 D 7

68:
10A  67 42
10E  7 5 N  (7 may be a 2 and 5 is upside down)
11B  68 15
11C  68 17
11D  68 19
12D  68 20
12D  68 21
01C  68 19
02C  68 27
02D  68 32
02E  68 30
02E  68 32
03C  68 34
03D  68 36
04A  68 37
04D  68 41
05C  68 42
05C  68 42
05C  68 43
05D  68 44
05E  68 46
06A  68 45
06B  68 47
07C  68 52
07D  68 52
07D  68 53

69:
09B   1 69
09B   1 69
09B   1 69
09D   5 69
10A  05 69
10A   6 69
10B   4 69
10B   8 69
10C   4 69
10D  10 69
10D  10 69
10D  10 69
11A  12 69
11C  11 69
11D  14 69
11D  15 69  (stamped 69 51)
11D  16 69
11D  17 69
12A  16 69
12B  17 69
12B  17 69
12B  18 69
12C  16 69
12C  16 69
12D  19 69
01A  19 69
01B  21 69
01B  21 69
01B  21 69
01C  21 69
01C  22 69
02A  25 69  (upside down 5)
02A  25 69  (upside down 5)
02A  25 69  (upside down 5)
02B  25 69  (upside down 5)
02B  25 69  (upside down 5)
02C  26 69
02D  28 69
02D  28 69
02D  29 69
02D  29 69
02D  29 69
02D  29 69
03B  29 69
03B  29 69
03D  28 69
03D  45 69 - replaced?
03D  33 69
03D  33 69
03E  33 69
03E  33 69
04A  33 69
04B  33 69
04C  33 69
04C  37 69
04C  37 69
04C  37 69
04C  37 69
04C  37 69
05A  37 69
05E  41 69
06A  41 69
06A  42 69
06A  45 69
06A  45 69
07A  48 69
08A   1 70
08A   1 70
08C  48 69
08C   2 70
08C   2 70
08D   2 70
09A   5 70
09C   5 70
09D   5 70
10A   9 70
10C   9 70
10D  10 70
10E  10 70
10E  12 70

Thanks!

[samz]

 I have a 12 70 tank on my 10E NOR Z/28
Painted on the bottom with some LeMans blue overspray on the ends.

[Jonesy]

I have 2 Van Nuys built 1969 Camaro's with original gas tanks.

My 11B car has 9 69

[Jonesy]

and my 02A Van Nuys car has 25 69 with an upside down 5

[RikerZ28]

Hey Guys, had some time today to look further into this gas tank coding. My seems to be off comparing it to the data complied so far.
I have a Norwood 1969 Z/28 Cow tag is 2D X-33, 124379N602562. Gas tank code is 25 69 (with an upside down 5)
For reference:
Axle Code BU 0218G2 (E)
Power Steering Code 041
Power Brake unit Code 39
NCRS Shipping report states Production date of 02/21/1969 

[69Z28-RS]

Sounds pretty close to me Riker...    tank date codes are NOT Julian dates or weeks, but instead are the week number since the first week that tanks were built for that year's model.   ie.   '69 Camaros likely began production in August (of '68), and your car is late February?  That would be close to 25 weeks wouldn't it?

[RikerZ28]

Thanks 69Z28-RS for taking a look, if I start from Sep 1 1968 week 25 will be Feb 9-14th which would correlate to a week before production date that I have from the NCRS. It just intersecting looking at the data so far there is no other 2D build week with a 25 69 tank code date.
Am I over thinking this??
Thanks   

[KurtS]

Overthinking. It's just off by 3 weeks, it was not a FIFO system.