This series started in mid-1977 at 100-HCA.
All 1977 plates used the narrow W in the NEW JERSEY die (this was the "standard").

There are 2 different "5" dies which were used on the tan and blue base NJ plates.
The original one has a shorter top line ... the newer one has a full-length top line.

Both "5" dies can be seen on the two plates below.

 

Dave Zullo

During 1978, 2 different varieties of the NEW JERSEY die were used - one with a narrow W and one with a wide W.


( Ironically, the die with the wide W has a smaller overall NEW JERSEY. )

The transitions between the wide W and the narrow W are pretty much random.
They flip back and forth at least 15 times between IDX and JPY.

By 1979, it looks like the narrow W die was used exclusively again.