1972-1976 Dimmer Switch question

[David L.]

I have a NOS 1997043 Delco dimmer switch that does not have the Delco-Remy casting on the bottom. After researching dimmer switches I have found that the GM # 1997028 is the part number listed in the 1963-1970 Corvette Assembly Manuals. I have had several 1997028 dimmer switches, used and NOS, over the past 4 decades and all had the "Delco-Remy" casting on the bottom.

According to Chevrolet Parts History (for service parts sold over the counter) GM # 1997028 was replaced with GM # 1997040 in Aug. 1971 which was then replaced with GM # 1997043 in May 1972. I assume that the 1997040 dimmer switch was issued to 1971 Corvettes and that 1997043 dimmer switch was issued to 1972-1976 Corvettes. I do not have any 1971-1976 Corvette assembly manuals.

My NOS 1997043 dimmer switch came in a Delco box with a date of Nov. 1990 on one of the box flaps. The bottom of the switch has a casting number of "22" and there is a "CC" casting on the top side of the flange part.
Question:
Do assembly line 1972-1976 Corvette dimmer switches have any casting names or numbers on them?
Dave

https://imgur.com/cLUZpS7

[Owen L.]

Re: 1972-1976 Dimmer Switch question

My '72 AIM shows the #1997043:

Screen Shot 2022-05-09 at 4.27.49 PM.jpg

[David L.]

Re: 1972-1976 Dimmer Switch question

Owen,
The encircled #1 and encircled #2 indicate when the change was made from the 1997028 switch to the 1997043 switch and the 3814824 screw to the 9431499 screw in the REVISION RECORD. Could you tell me the date? The date is when the change on paper was made, not the actual date that the change was made on the assembly line.
Dave

[Owen L.]

Re: 1972-1976 Dimmer Switch question

Here is a screenshot of the change table:

[David L.]

Re: 1972-1976 Dimmer Switch question

Thanks Owen
Dave