The options ordering information I have dated February 1, 1966 has this note for the K19 option.
"Approved by the state of California and exclusive to California vehicle registrations only."
I think exclusive is the key word. Ok, this is in 66 but I would assume this to be the case in 67 also. Maybe someone with 67 information can chime in. We also know that Fremont built vehicles with K19 were also delivered to surrounding states (particularly in Oregon) and sold outside of California, but the intent was apparently to have these vehicles available where Californians might purchase their cars. In 1966, K19 sales numbers can account for most of Fremont's production. In 1967, as I recall, Fremont produced a larger number of cars than the K19 numbers, so that implies that Fremont also built a significant number of 49 state cars in addition to the K19 cars. I think all the K19s sold would show up as optional sales. I would agree that Fremont could have built EG engined cars for delivery outside of California, but I don't think that any EX coded engines would have been installed outside of Fremont.
My 67 data shows about the same thing but the figures don't add up. Let me say first the option numbers reported in Tailfins & Bowties do NOT inlcude options that were included within other options such as:
L35 engines shown sold from 1966 thru 1968 that were base engines in the SS396 just like the LS5 engine is not shown with any option sales in 1970 because it was the base engine in the Z15 SS454 option. Based on that, I don't believe the figures for standard or required items are included in
"GM Air Injection Reactor: Approved by the state of California and exclusive to California registration
. Available only when closed engine positive ventilation is ordered." To me this means the K24 option is required along side the K19 option.
The 67 figures for K19 (A.I.R.) is 42,147, the figures for K24 (closed pos vent) is only 40,515 and the production reported for Fremont is 61,500. The "...exclusive to California registration
..." and sales numbers would indicate 19,353 Chevelles built at Fremont were apparently for dealers outside of California; that's reasonable. If K19 (A.I.R.) was only available when K24 (closed pos vent) was ordered, why would the figures for K24 be 1,632 less than K19? Odd...
Further, K24 says...
"Ventilation, Closed Engine Positive:
Included when 325-hp 327-cu-in or 350-hp engine is ordered." Note nothing is said about K19 or California.
So, would the K24 sales figure of 40,515 include those two engine orders (4,048 L79 plus 17,176 L34 where it's included) as well? Now we've gone from 1,632 fewer K24 than K19 (that required it) to 22,856 K24 sold without K19. The AIM shows K24 on 6-cyl engines as well as the 283, the L30 327 as well as the L35 396 (noteably lacking the L35 & L79 that automatically came with K24).
Devil's advocate here...
The reported options sales figures are why I tend to think the K19 "...required for California registration
..." (not California production) units are not included in the 42,147 reported sold as options. Additionally, since K19 required K24 and K24 figure is lower than the K19 by 1,632 those wouldn't be included, either in the California registration requirement nor any K19 options sold outside of California. Other production plants that could have installed K19 (and required K24) for other areas of the country and K24 sales reported would be for every engine where it wasn't required (K19/K24) or standard (L34/L79).