69 cowl air cleaner flat bottom/grooved

[john302]

Does anyone know the month/week they stopped using the flat bottom cowl air cleaner and started using the grooved one?July? august? thanks John

[william]

This 09D survivor Z/28 has the later air cleaner with the bead in the base. Best guess, late August or so.

http://www.camaros.org/forum/index.php?topic=12083.0

[68camaroz28]

This 09D survivor Z/28 has the later air cleaner with the bead in the base. Best guess, late August or so.

http://www.camaros.org/forum/index.php?topic=12083.0

Another point in the thread was paceme (Steve) discussing that 70 Chevelles could be optioned with the same air cleaner and they have been documented with the later design. 

[69Z28-RS]

And there are later cars with original Cowl Air cleaners with the flat bottom... so it would seem it's like a lot of the late '69 parts..  intermixed '69 and '70 parts over several weeks or months...