what is my 350 out of?

Ive acquired a 350 block, and its casting number is 10054727. Ive been searching to see what it came out of, and I havent had much luck. I know that it was made in canada....hence the casting "CANADA" on the block, and its a 2 bolt main, but some were built as 4's as well. 1 piece main seal. There's no heads, so I cant run numbers on those either. Pretty sure its not a GM motor, due to the lack of an engine number engraved on the deck....like GM is known for. Anybody got any ideas?

The fact that it was cast in Canada makes me think late model 350.

Here is what it says on chevymania.com
10054727 350 86-up 155-205 Car & Truck 2-bolt Passenger stick 1-piece seal