Perhaps, rather than VIN designations as to body size designations, it might be interesting to look at some of the early "internal Chrysler" designations for these body series designations?
Reason I say that is that GM didn't really start to use the VIN designations until about the earlier 1970s, BUT the Internal-use body designations had been around since the 1940s in a slightly different orientation. The "small" cars were Chevrolets and were "A" bodies, with the next-larger cars being "B" bodies, and the "C" body being the Olds 98, Buick Electra, and Cadillacs. But this was also back when there was only ONE general size of car, "full-size", corporate-wise. But with the introductin of the 1960-new "compact" size front engine/rear drive) cars (i.e., Chevy II, Cutlass), then the "intermediate" size front engine/rear drive) cars in 1964, the ranges got a bit wider. With the Biscayne/BelAir/Impala remaining "full-size". These designations OR actual model names were also "parts book designations", too.
By the time I got into the GM dealership parts dept. work, I was already fully aware of the Chrysler-style body designations. So seeing something of the same thing in GM by that time, made sense to me. When I started digging into the 1964-'72 parts books, I noticed the non-letter designations and the transition into the letter designations. So, for clarity, I just projected those letter designations backward to keep things standardized in my mind. This also made things easier as I would use the "modern" designations to describe 1960s-era cars in my notes. Therefore a "BL69" would be a Chevy Impala 4-dr sedan whether in 1960 or 1980. Plus, easier to scirbble on the paper, too!
In this orientation of 1960+ Chrysler Internal Designations, the Valiant/Dart would be the smallest and "A" cars, with the "full-size" cars (CPDD) being "C" cars, and the largest most majestics Imperials were "D" cars. By observation, the "C" and "D" designations might be projected rearward for many decaides, too.
The "suddenly-downsized" Plymouths and Dodge full-sized cars of 1962 would later lead to the 1965 "B" body cars, by observation. But the parts book designations were still "P" and "D", for Plymouth and Dodge, respectively. Using the model series names and intials kept things simple for the service and sales sides of things. With the model year designation being a completely different letter designation (for VIN purposes, it seems).
Now, were the 1963-'64 Chryslers just enlarged 1962 Plymouths or Dodges, with a longer wheelbase and up-rated chassis items? As engineering transitioned from the 1957 models into the more modern orientations of the up-coming mid-1960s.
My question would be: Might the body-size designations that we normally deal with in the 1965 and later model years also be related to some internal Chrysler body series designations, too? Perhaps there might be some "Collectible Automobile" or "WPC News" magazine articles which might offer more information in this area? Or somebody with knowledge of the Chrysler internal designations, themselves?
Just some thoughts,
CBODY67
