Is this an original ID Plate for a 73 THM 400 Transmission

[Gil D.]

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I have attached a picture of the 73 Judging guide for the THM 400 Riveted ID plate and my ID plate. My plate does not have the pink silk screen, but it has all the proper numbers such as 73 CK. My car is a 73 L48 w an M40. Also the number to the right of the rivet, a Julien date of 202 matches. This day, when added to the 72 calendar, yields a mid July transmission build date. My car is an August 72 (1st month) build date. I believe the ID plate is original, and the guide is based on few samples....thoughts?

[Terry M.]

Re: Is this an original ID Plate for a 73 THM 400 Transmission

I have seen a lot of these tags with the paint worn off or removed by chemicals. I think a good pressure washer would blast the paint off the tag. On the other hand, the tag is in a location that makes assess to it problematic unless the body just happens to be off the frame or the transmission out of the car for some reason.

There were probably tens of thousands and maybe hundreds of thousands of TH transmissions built over many GM car and truck lines and to think they were all built according to the design specifications, especially something that doesn't affect performance, is foolhardy.

Share the history of your car and one might be better able to divine the "why" of this anomaly but lacking that I would caulk it up to "stuff happens".

Enjoy your Corvette. The TH 400 is a great automatic transmission. Enjoy it.

[James G.]

Re: Is this an original ID Plate for a 73 THM 400 Transmission

The silk screened paint or ink is gone, but yes I believe that the tag is legit and IMHO has never been removed.
BTW I have seen many which are missing the silk screened color application.
As you realize the stamped numbers are the important ones.
Your vin should also be on the case, IIRC on the side of the pan rail under the modulator maybe?

[Terry M.]

Re: Is this an original ID Plate for a 73 THM 400 Transmission

The silk screened paint or ink is gone, but yes I believe that the tag is legit and IMHO has never been removed.
BTW I have seen many which are missing the silk screened color application.
As you realize the stamped numbers are the important ones.
Your vin should also be on the case, IIRC on the side of the pan rail under the modulator maybe?

Jim
The partial VIN on M40 transmission is on the driver's side pan rail. Usually partially or completely obscured by the transmission shift linkage.

Good job mentioning that because ultimately that is what links the transmission to this car.

[James G.]

Re: Is this an original ID Plate for a 73 THM 400 Transmission

Thanks Terry,
I knew someone would correct me on the vin location, as it would have been a lucky guess, but figured I should mention it.

[Gil D.]

Re: Is this an original ID Plate for a 73 THM 400 Transmission

James thanks. Yes Gary Boselman suggested the VIN may be on the driver's side of the case just above the pan. The VIN stamp for the transmission is not mentioned in the 1973/4 Judging guide however. I will check thanks

[Gil D.]

Re: Is this an original ID Plate for a 73 THM 400 Transmission

Thanks Terry. This was a one-owner car until I bought it in October of this year. It was purchased in San Diego CA and was there with the owner for 51 years. It was one of a three Corvette purchase by the Father, Daughter and her brother, a mjpr league pitcher for the Oriels. I have a lot of great family history including family pictures, all registration receipts, title, window sticker, owners manual, etc. Block is original to the car. Full power options w pb, pw, ps, and tilt Tele. Thanks for info