News:
11354 were made and they start at 100k so 6444 and thats were my knowledge stops.
That one is fairly early. The highest VIN I have seen for a 1974 Challenger so far ends in 397584, but I do not have the SPD for it. Likely sometime in April of 1974.
From the Challenger Registry a '74 car is VIN # ends 1156xx and his build date is 1973 - NOV - 24 so yours might be a Sept/Oct '73 built car? http://challenger-registry.com/index.php?option=com_sobi2&catid=14&Itemid=34
Year: 4 = 1974
Sequence Number: 106444 = 6444th Vehical Built
Model year. Which in this case started in July 1973.