They were Chevrolet 1.5t and up built in Ottawa using a mix of GMC and Chevy parts as well as some Canadian parts. They were marked as "Made in Canada". They are basically the same as US built,yet some parts did not interchange. They hoped that it would help Canadian sales if a truck was offered as built in Canada. Also,British Commonwealth countries,like Australia,put high tariffs on US built products because the US really didn't import anything from them (didn't need to) and AUS didn't want imbalanced trade. The tariffs were minimal between British commonwealth countries because England imported a good bit from AUS. So,this was a way for GM to offer trucks at a more affordable cost.
Here is a '35,'36,and '40: