It might have been Golden Horseshoe in Toronto. This track was only in operation for a few years, right around 1970. I was there once with a friend that raced a 1969 428 Torino. John Petrie's 'Cuda is to the left. He was sponsored by Argyle Chrysler in Toronto. This track likely got swallowed up by Hwy. 401 or 407 expansion.
Or, it could have been Cayuga Dragstrip, southwest of Toronto, off Hwy. 3. A strip that opened around 1955, and is still running today. With its proximity to Fort Erie/Buffalo, it was a popular track for racers from New York, Ohio, and Pennsylvania.