To my knowledge, which radio your car was optioned with has nothing to do with what style antenna the car had. It was a build date /assembly plant/ vendor supply issue.
I am not sure what the change over date is
for each assembly plant.

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