68 VIN number/ build date

[terrible one]

Just an FYI...since nobody else has seen fit to say this, but - the metric system wasn't adopted in Canada until the end of 1977 when all road signs were metric and all new cars had metric odometers and speedometers.

Thanks for the heads up, I didn't know that!

[terrible one]

  The date codes on the individual part is for the part only.  Same goes for K frames your car got what was in the bin when that car came through the line.  For example, my car is a documented survivor that had 36k miles when I began the restoration.  The only things removed from this car was the fan blade and the tires and rims.  Build date was 4/69 the original parts pulled had dates from 1/69-4/69.  The block was 2/69. 

That has been my understanding. So far I've found a range of dates like you. The 3 digit codes like the glass are 2/68, 3/68 and 4/68 but almost all of the 4 digit codes (like on the dash speaker, parking brake struts, etc. have been mid to late April. Knowing that is when the individual parts were made definitely helps to narrow down a "window," even if you don't have or disregard the SPD. 

[6bblgt]

sorry I missed this one last time around 
CHARGER ONLY Spring '68 colors:
the earliest 331 Charger (of 25) I know of has a 325 SPD & it's the same color as 1969's R4 (not R6 as stated above)
the earliest 661 Charger (of 10) I know of has a 307 SPD & it's the same color as 1969's F8

Chrysler also had a "Spring Special" color 441 which became 1969's Q5

[MO68CHARGER]

Just came across this thread... I have a '68 R/T 33-1 red car. Pulled it out of a barn last year. Been trying to find out how many were painted that color. Very limited info out there! I am restoring it and going back to the original color btw!

[Homerr]

We're slowly accumulating some info here, see stats page.

https://sites.google.com/site/1968chargerregistry/