TH-400 tag numbers...What do they mean????

I have a th-400 and theres a small tag revited to the side with some numbers stamped on it. It reads 71-CA 21682
Any help would be appreciated.

 

SOG, without running down to my book, I am going to speculate that is from a 71 Cadillac.
Tom

 

codes that start with C are chevy, not caddy. Caddy is A.

anyways, it's a normal duty p***enger car 402 TH400 from a 1971 chevy. The good ones are CY....

 

Thanks guy much appreciation.

 

SOG, sorry for being lazy about it and Squirrel, thanks for providing the right stuff. That is what I get for not walking 20 feet downstairs and back!
Tom