you might be right about the CDN ones, particularly as both were assembled at Oshawa, but also note that most of the differences would only be detectable with digging and measurement - like slightly heavier shackle bolts, or the difference in frame material thickness or length, and the difference in the front cross member and radiator frame - the CDN GMC's did use Chev engines, which I thought changed in 55, but a buddy got a good original 58 from the praires that had a 261 - there just doesn't seem to be much hard info about GM Canada's production in that era
Bill
