Water pump rotation

Early to me at least would imply 80-84. I've had one of each - 80, 81, 82, my niece has an 83, and I had an 84 - all with AC. No serpentine belt. So I guess that sort of messed up the early bit maybe?

It fits that Canadian built cars could differ - not saying it's absolute, but it fits.
For one thing we've noted that the Canadian built Eagles had a vacuum can up under the fender, behind the plastic liner, while Eagles like mine all had them in the engine bay. That at least I've seen first-hand - but can't say I have seen ALL Canadian Eagles so it may not be a rule. 
But it does show there were some differences - why? I sure don't know!

Almost all Canadian built cars have some minor differences. Just a different assembly plant doing things slightly different in some cases, like the location of the vacuum storage tank Billd mentioned. Earlier cars had differences due to requiring as much Canadian built content as possible to reduce taxes (pre 1966 AutoPact). They had a few different manufacture parts not mentioned in the TSMs, and some just minor quirks. All 64-65 Canadian cars (maybe earlier) had white headliners. No one hardly noticed the headlinier, so they reduced costs by not having to stock several different colors -- just made them all white and stocked one!

All the CA spec cars could have been built in Brampton. Something to check if anyone has a CA spec serpentine belt car! Brampton was much smaller than Kenosha. If they needed to make one that way they likely made them all that way to save on the number of parts stocked and streamline the assembly line. Again, just speculation here... but something to look for.