The first thing to keep in mind is that your car was not built on April 26. 4/26 Is one of 2 "scheduled" production dates that all A12 M code B bodies carried . But the car could have been built several weeks in either direction.
For example , the 1970 A13 B body Superbirds were built between October and December 1969, but ALL of them have an SPD of November 30 (B30).
Back to your car , I'd say a late Jan casting date is right about where it should be.
Now, what is your engine assembly date found on the pad by dist.
It should be probably March-April

Greg

Wards Classic Car Radio Repair Specializing in restoration and sales of Mopar A B E body radios
We can restore YOUR radio usually in less than 7 days
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gregward@mchsi.com
phone 256-852-0955


gregward@mchsi.com phone 256-852-0955