When Bumpy and his crew are picking up the drug shipment in Montreal there is a sign that has the Canadian Maple Leaf flag on it. However, the time line is 1964 but the new Canadian flag was only adopted in 1965.
Del says that they have a 7-hour drive to get back to Harlem from Canada, but right after says that they are going through the Windsor/Detroit border. Assuming they are already close to Windsor, it's a 9.5 to 10 hour drive from Windsor to Harlem.
In previous episodes it is said that the shipment from Marseilles is to be picked up in Montreal. However in this episode they are supposedly returning to Harlem via the Windsor/Detroit border. This makes no sense if you consider the geography of the three locations: Montreal is about 225 miles due north of Harlem, while Windsor is about 625 miles west of Harlem.