I am trying to determine the actual production date of my 1972 Cutlass Supreme Convertible and . This is my 3rd 1972 in the past 35 years. My 1st car was built in Lansing and sold new in Canada and I have been able to find out that the production date was November 15th 1971. Serial number was 141830.
My current convertible was also built in Lansing with cowl tag date 11B 2nd week of November. Car was sold new in Tulsa Oklahoma 12/14/71 as per original title. Serial number is 141084 which means it was 746 cars before my 1st car. Anyone have any idea how many cars were built per day/shift at Lansing in November 1971?

 

In answering a similar question about my Vista Cruiser, I estimated that Lansing produced about 650 cars per working day in 1970.

Assuming production in 1972 was similar to 1970, your cars were made about a day apart.

 

the serial number sequence has little to do with actual production sequence
body number on the cowl tag will give you better timing related to build dates

 

Apologies, I didn't read carefully enough. I, too used the Fisher number to estimate build date.

 

Try finding a broadcast card inside the car, not to be confused with a build sheet. Usually found in the rear seat springs or stapled to the underside of the front carpet drivers side. That date is right at the top left corner.

 

Broadcast card long gone. Car had a full frame of rotisserie restoration in 1993 by the previous owner after being brought up to Ontario Canada.

 

Body number is 291982 with 11B as the date. Just trying to narrow down the build date.

 

Based on the November 15th production date of my 1st car as provided by Vintage Vehicle Services here in Ontario Canada (for cars built in Lansing and sold new in Canada) I am guessing the build date is November 13th or 14th 1971