cat or not that is the question

[brandnew84]

Ok, here goes.
I own a canadian chevy big 10 pickup, although the previous owner turned it into a gmc sierra classic a vin check told me it is really a chevy k model heavy duty.
I am getting conflicting results searching to find out if my big 10 from canada came with a cat from the factory...it's a 305 4bbl 4x4...from what I could find out canada did not adapt to the emission law until the 1897 model year and the big ten came without cats.
If anyone can shed some light on this subject I will be able to keep the little hair I have left on my head as my restoration/build comes to an end.
Thank you all,
Mark
AKA brandnew84