74 duster codes

L1 - Assembly line 1

L2 - Assembly line 2

The numbers after the L1 & L2 on 1974 Hamtramck cars range from 001 to 999. I do not have a whole lot of 1974 Hamtramck info here, but I looked into it extensively a while back & I could not find a meaning to it or why they did it.