Hard Top Window Date Code
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,581
Likes: 28
From: Spring, Texas
Hard Top Window Date Code
My hard top has "M72" as part of the markings in the lower left corner of the (back) window. I assume this is the date code? If so, can someone decode it properly? I've made a few guesses but want to confirm.
Team Owner
Joined: Sep 2006
Posts: 31,173
Likes: 4,250
From: Westminster Maryland
Hi SA,
The 'M' and a number that you listed appears on all glass.
The number describes the glass.
For instance there is a different number for laminated plate, tempered plate, or tempered float glass, and for tinted or clear glass.
The 'M72' you found indicates 3/16", tempered, 'float' glass.
Regards,
Alan
The 'M' and a number that you listed appears on all glass.
The number describes the glass.
For instance there is a different number for laminated plate, tempered plate, or tempered float glass, and for tinted or clear glass.
The 'M72' you found indicates 3/16", tempered, 'float' glass.
Regards,
Alan
Burning Brakes
Joined: Jan 2009
Posts: 766
Likes: 97
From: Lake Norman, NC
Original glass did have date coding scribed into it. Look again at the information scribed in the lower left corner. The date (year/month) code will be depicted in 2 alpha characters. Post the characters here and we can let you know the date of glass manufacture.
Hope this helps.
Hope this helps.
CF Community Team
Joined: Mar 2007
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From: Delaware
St. Jude Donor '25
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Team Owner
Joined: Sep 2006
Posts: 31,173
Likes: 4,250
From: Westminster Maryland
Hi,
The windshield logo and date code are interesting in that it was etched on the outside of the glass, but in reverse, so it's read from the interior.
You can just feel the etching with your finger tip or fingernail.
The AS1 was between the two layers of glass on the windshield.
Regards,
Alan
The windshield logo and date code are interesting in that it was etched on the outside of the glass, but in reverse, so it's read from the interior.
You can just feel the etching with your finger tip or fingernail.
The AS1 was between the two layers of glass on the windshield.
Regards,
Alan
Last edited by Alan 71; Sep 23, 2014 at 02:37 PM.
Le Mans Master
Joined: Jun 2006
Posts: 6,398
Likes: 1,226
From: Tampa Florida
Hi,
The windshield logo and date code are interesting in that it was etched on the outside of the glass, but in reverse, so it's read from the interior.
You can just feel the etching with your finger tip or fingernail.
The AS1 was between the two layers of glass on the windshield.
Regards,
Alan
The windshield logo and date code are interesting in that it was etched on the outside of the glass, but in reverse, so it's read from the interior.
You can just feel the etching with your finger tip or fingernail.
The AS1 was between the two layers of glass on the windshield.
Regards,
Alan
For my April 19, 1971 build date, my glass codes are:
Left door, NN, Jan. 1971, etched on inside
Right door, IT, June 1970, etched on inside
Windshield, GN, April 1971, etched on outside in reverse.
Team Owner
Joined: Sep 2006
Posts: 31,173
Likes: 4,250
From: Westminster Maryland
Hi 71,
Interesting!
Your right-side door glass is likely an example of why the length of time before production is increased to 12 months for glass rather than the 6 months used for the vast majority of dated parts.
Regards,
Alan
Interesting!
Your right-side door glass is likely an example of why the length of time before production is increased to 12 months for glass rather than the 6 months used for the vast majority of dated parts.
Regards,
Alan
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,581
Likes: 28
From: Spring, Texas
2nd Gear
Joined: Nov 2021
Posts: 2
Likes: 0
The 'M72' you found indicates 3/16", tempered, 'float' glass.
Hi SA,
The 'M' and a number that you listed appears on all glass.
The number describes the glass.
For instance there is a different number for laminated plate, tempered plate, or tempered float glass, and for tinted or clear glass.
The 'M72' you found indicates 3/16", tempered, 'float' glass.
Regards,
Alan
The 'M' and a number that you listed appears on all glass.
The number describes the glass.
For instance there is a different number for laminated plate, tempered plate, or tempered float glass, and for tinted or clear glass.
The 'M72' you found indicates 3/16", tempered, 'float' glass.
Regards,
Alan
Le Mans Master
Joined: Jun 2006
Posts: 6,398
Likes: 1,226
From: Tampa Florida
Alan hasn't posted since 2018. Here is a link that's been posted on this forum before that shows these codes. Scroll down about half way and you will see the decoding information for M24 and M72.
http://www.camaros.org/glass.shtml#marks
Also, here is a reference for LOF date codes.
https://www.corvetteactioncenter.com...3/c3glass.html
Last edited by 71 Green 454; Nov 5, 2021 at 07:57 AM.
2nd Gear
Joined: Nov 2021
Posts: 2
Likes: 0
Hi Rod,
Alan hasn't posted since 2018. Here is a link that's been posted on this forum before that shows these codes. Scroll down about half way and you will the decoding information for M24 and M72.
http://www.camaros.org/glass.shtml#marks
Also, here is a reference for LOF date codes.
https://www.corvetteactioncenter.com...3/c3glass.html
Alan hasn't posted since 2018. Here is a link that's been posted on this forum before that shows these codes. Scroll down about half way and you will the decoding information for M24 and M72.
http://www.camaros.org/glass.shtml#marks
Also, here is a reference for LOF date codes.
https://www.corvetteactioncenter.com...3/c3glass.html
Instructor
Joined: Oct 2021
Posts: 240
Likes: 82
From: Pittsburgh, Pa. da 'burg
71 green 454,
A little off-topic but, does your November 69 hardtop have a chrome, triangular, mounting bracket at the lower-center of the rear bow? A chrome carriage bolt passes through the bracket and through a ferrule in the center of the decklid, and acts as another mounting point for the hardtop. I'm helping to document when GM added this bracket to the hardtop. So far, information shows that it was sometime in late '69. The approximate serial number is unknown.
Oddly, on my '69, I have a '71 vinyl covered hardtop dated nn (Jan '71) that I bought many years ago. My car was built in November '69, just as your hardtop is dated. FWIW.
R on B 69
A little off-topic but, does your November 69 hardtop have a chrome, triangular, mounting bracket at the lower-center of the rear bow? A chrome carriage bolt passes through the bracket and through a ferrule in the center of the decklid, and acts as another mounting point for the hardtop. I'm helping to document when GM added this bracket to the hardtop. So far, information shows that it was sometime in late '69. The approximate serial number is unknown.
Oddly, on my '69, I have a '71 vinyl covered hardtop dated nn (Jan '71) that I bought many years ago. My car was built in November '69, just as your hardtop is dated. FWIW.
R on B 69