Copied this from a post over on the H.A.M.B. Wasn't sure where to park it but I thought it was a very good read. I have no clue as to who the actual author is.

There doesn't seem to be a lot written about the history of the Canadian
Pontiac. I may be wrong but I just haven't been able to find that much. It
occurred to me that there are probably many who do not know the reasons why a uniquely Canadian Pontiac existed at all. I don't claim to be the
definitive historian on Canadian Pontiacs but I do know at least part of the
answer to how the General Motors 7000 series vehicles commonly called
"Canadian Pontiacs" came to be.

I worked for General Motors as an engineer for 37 years retiring in 1998 so
my tenure there spanned a substantial portion of Canadian Pontiac
development. The development of the 7000 series Pontiac did not happen
overnight but was rather a progressive departure from the US design brought
on by economic considerations unique to the Canadian market. The Pontiac
name plate was introduced by Oakland in the United States in 1926 as a lower
price Oakland model designed to fill the price gap between Chevrolet and
Oldsmobile. It was so successful in its mission that by 1932 the Oakland
brand name was dropped and Pontiac achieved full status as a brand
divisional name placed squarely between Chevrolet and Oldsmobile.

While its relative market position has never changed to the present day and
Pontiac remains the second best seller for GM in the United States, it wasn't
very long before Canadian requirements for the Pontiac began to diverge from
our American counterparts. The decision to produce a Canadianized version
of the Pontiac was not taken in one step but was rather a progressive
departure from the US design driven by a succession of economic
considerations unique to Canada and by advancements in automotive design and
production methods that drastically increased investment cost to produce a
separate vehicle.

The first factor was the limited size of the Canadian market for
automobiles; in total less than 10 percent of the US market in any given
year. Because of this limitation no single vehicle line except for Chevrolet
offered sufficient sales potential for a Canadian dealership to exist and so
General Motors of Canada Ltd. developed a marketing strategy early on which
offered dealer franchises based on combined product line packages, the most
common of which still exists today as Chevrolet/Oldsmobile/Cadillac
dealerships versus Pontiac/Buick/GMC. Similar franchise strategies were
developed at Ford and Chrysler as well during the same period.

Almost from the beginning at General Motors of Canada there was a
concentrated effort to equalize the product packages offered between
Chevrolet/Olds/Cadillac and Pontiac/Buick/GMC dealers. The problem in
maintaining such a balance was Chevrolet volume which in many years equaled
or exceeded the total sales volume of Pontiac, Olds, Buick and Cadillac
combined. To combat this Pontiac was selected in an attempt to provide an
entry level vehicle which could compete with Chevrolet in price and design
features head to head thus giving Pontiac dealerships a means to compete
directly in the entry level market.

In attempting this GM quickly ran up against additional factors that made
use of the US Pontiac design less than acceptable. Canadian importation law
imposed duties of as much as twenty-two percent on finished vehicles and
automotive components coming into Canada. With the exception of Cadillac, it
was not economically viable to import finished vehicles into Canada at high
duty rates. As a result from an early period and until the automotive free
trade agreement (autopact) was signed between Canada and the US in 1966, all other GM models were produced in Canada.

For the most part components to complete these vehicles on Canadian assembly lines were imported from the United States. The exception of course was Chevrolet whose volume justified the high investment necessary to
manufacture major driveline components such as engines and transmissions.
Keep in mind that each division in the US shared little in common when it
came to chassis so in order to produce anything but Chevrolet in Canada it
was necessary to import and pay duty on engines, transmissions,
differentials and virtually all other chassis and sheet metal components for
these cars.

While Olds and Buick enjoyed enough price flexibility to do this, Pontiac
was never going to compete head to head with Chevrolet in Canada with an
American model Pontiac assembled in Canada from imported parts on which duty had to be paid. Something had to be done to lower Pontiac's price both in
terms of investment and component cost.

The answer became the 7000 series Canadian Pontiac. To avoid duty on major
chassis items such as engine and transmission it was evident that such items
must be produced in Canada. For many years they were. The Pontiac L-head
engine was probably the best example of this, the straight six version of it
being produced in Canada for many years. But by the mid 1950's the greatest
sustained yearly model change program in automotive history had begun. When Pontiac Motor Division dropped the L-head engine in 1955 even the most
optimistic sales figures could not justify separate Canadian tooling for the
American Pontiac V8 engine or the hydramatic transmission it was teamed
with. Furthermore the US Pontiac no longer offered a six which would put
Pontiac at a disadvantage against Chevrolet in the Canadian market. In a
decision that departed from everything that was holy in the autonomy of the
US car divisions, it was decided that a hybrid based on a Canadian produced
Chevrolet chassis which offered both a six and a newly introduced V8 was the
only way Pontiac could compete in Canada. To save on investment the Pontiac
would be produced on the same assembly line as Chevrolet. Similarly the
Pontiac and Chevrolet versions of the Chevrolet small block V8 and
Powerglide transmission were also manufactured together as were rear axles,
brakes, exhaust systems, radiators, and much more.

By 1958 with the introduction of the Chevrolet 'X' frame the transformation
was complete and 7000 series Pontiacs were by then a much different car from
their US look-alikes. Mechanically they now shared virtually everything
with Chevrolet but outwardly in appearance it was hard to tell them apart
from an American Pontiac.

It is a common misconception that all economies of scale were achieved in
one direction by commonizing Pontiac with Chevrolet. There are many examples
where this process worked in reverse such as the uniquely Canadian Pontiac
air cleaner which was installed on Canadian produced Chevrolet small
block V8's as well and the common electrical wiring harness which is more
Pontiac than Chevrolet and differs in design from both us Chevrolet and
Pontiac.

And so for many years Canadian Pontiac fulfilled its purpose as a Chevrolet
fighter, in some years almost equaling Chevrolet sales in Canada. With the
introduction of compact models in 1962, the same philosophy drove uniquely
Canadian Pontiac models of these Chevrolets starting with the Acadian
version of the Chevy II. In fact as early as 1959 a Pontiac version of the
Corvair was tooled for Canadian production but was cancelled just weeks
before introduction. It too was initially to be called the Acadian.

But the autopact of 1966 changed the outlook for the Canadian auto industry
for all time. For one thing it began the process of rationalization to
allocate high volume production of fewer models exclusively to Canada in
exchange for the duty free importation of other models and components for
other models from the united states. Canadian Pontiac was the eventual
victim of this rationalization.

Though its uniqueness continued for several years after 1966 by the early
1980's those Canadian Pontiac model names that still existed were little
more than Chevrolets with Pontiac name plates and many of them were
manufactured in US assembly plants for the Canadian market. In addition many
of the American Pontiac models had found a place in the Canadian market and
some of these were manufactured in Canada for sale both in Canada and United
States.

But there was one last hurrah for Canada. When Pontiac motor division
prematurely dropped its full size car line and downsized the Bonneville to
intermediate size status US Pontiac sales plunged. Canadian Pontiac
Parisiennes were hurried into production for the US market to bolster sales.
By this time the Parisienne was little more than a Caprice with a Pontiac
style grill so the following year Fisher Body actually resurrected old dies
to bring back the previous Catalina rear end styling to make the car more
distinctively Pontiac in appearance. For the American market. It continued
in production for some years still bearing the Parisienne name and still
proudly displaying the made in Canada stickers throughout US showrooms.