Yes, those are Canadian heads - they were cast and machined and assembled on an engine built at McKinnon Industries (GM Canadian subsidiary, now called the St. Catherine's Engine Plant in Ontario); McKinnon-built engines were used primarily at the Oshawa, Ontario and Ste. Therese, Quebec assembly plants, and had a "K" prefix on the pad, although McKinnon also supplied some engines for a few U.S. assembly plants (but none for Norwood or Van Nuys).
