I was wondering what these numbers mean on my 66 442.
I found two sets of them on the driver side lower rocker panel.
They do not match my vin # nor my data plate and is only on
the body. The car, as far as I know, has never been separated
from the frame until this year when I decided to do a body off
frame restoration.

Please advise me, and thanks ahead of time.

P.S...there are two sets of these on my rocker panel, one of the sets
have left the letter Z and 21 off. That is, the last 3 numbers/letter.
Ie: 13211 and about a foot further down the rocker another set found
13211Z21

 

I'm still at a loss as to what these numbers stand for.....if anyone knows, please give a shout my way.

Thanks ahead, 66kidscar

 

They are a production/date coding. Without the key to the code (I don't know anyone who has it), you won't decode them.