Tim, I may have misspoke, it could be a 261 with a earlier valve cover.
I can tell by the ribbed cylinder head it is a 18 bolt head, first used in 1953.
I believe Canadian 216's used the 1950-52 235 head. That head can be identified by the smooth contour between #1&2, and 5&6 spark plugs.
Carl, it could be a 1953 PG engine with Captains bars, or a 1953 stick engine which would have the oil distributor on the drivers side and no Captains Bars.
