You guys do realize that the scheduled production date has very little to do with either the sequence number or the day the car was actually built, right? The
only place that shows the correct, actual build date of a Chrysler vehicle of that era is the
original window sticker. Not the door sticker, data tag, build sheet, etc. The window sticker was printed the day the car was built. The SPD is just the day they knew they'd have all the parts on hand to build it, nothing more. The sequence numbers seem to be anything but sequential as far as chronological build order, despite what we've all been told over the years.
From the '73 Challenger 340 I owned when I was 17:
JH23H3B
330963SPD:
122 (January 22, 1973)
Actual build date:
0201 (February 1, 1973)
By all accounts, that sequence number is pretty high for a January/February build date. I was the second owner of the car, which I bought on June 24, 1988. It was a 15-year-old, very-rusty used Dodge with a cool 4-speed shifter, not some collector's item. I have every piece of documentation for the car from the MSO to the build sheet (even the original trade-in agreement), all of which I got with my $500 prize that sunny Thursday evening. VIN, data tag, and other documenation trickery simply didn't exist back then.
For comparison purposes, the '73 Charger Rallye 340 I owned three years later was VIN #WH23H3A
201396 and had an SPD of
314 (March 14, 1973) per the data tag I still have. I don't have the window sticker for the Charger, but suffice to say it was built sometime after March 14th. Now, I can buy into Hamtramck being busier than Lynch Road, but I seriously doubt Poletown had kicked out over
129,500 more cars by the end of January than the boys at Lynch had almost two months later. Again, I bought that car in 1991 for $1,100 so it's not like there was tomfoolery involved with numbers. They all matched, and I still have the 340 block in my garage from the Charger.
In case you missed the "Last Hemi Charger" debacle between Tim Wellborn and RK Motors, click
here to read what's been accepted as the final resolution. It explains quite nicely why your SPD and sequence number mean exactly
squat. The SPD is the day your car wasn't built, almost guaranteed, but you can at least be sure it wasn't built
prior to that 3-digit date code.