I found a Muncie transmission ID tag stamped 3981710WY. Can anyone decode this for me or let me know of a source book for decoding. Also, what tag was used on a 70 Chevelle M22?

try scrolling down to transmissions. wally the moderator is a geru on them muncies.

I have a Chevelle Report from Dec. 1993 and it list all the tags for 64-72 Chevelles. Has nothing on the 3981710WY and lists
tag 3978766-WO for 70 Chevelle M22 and also 3968012 but states it was discontinued 3-11-70