weird engine manufacture code

[70CitrusZ]

Wow this is new...Is there actually proof that Canadian L36 were non-smog?. A similar issue came up in the past when I was restoring my 70 Z-28.
Its some sort of old wives tale, and In that instance (F Bodies) it has been proven that Canadian "sold" cars DID indeed all have smog just like their American counterparts, (of course they were all built in the U.S.) unlike popular belief that Canadian Z's were somehow smog exempt.

This would certainly confirm the reason for the different engine codes if this were true on 68 Canadian built cars which could include Canadian Pontiac and Chevrolet A and B bodies, and possibly X as well?.

Can anyone else confirm this information is true?

This would mean that 3S was Canadian or non-smog L36 with M20 trans, and 3T was non-smog L36 with M21 trans.

If this is confirmed it solves the mystery! ...It also means I have to find some undrilled exhaust manifolds...
Mark.