Canadian-built '62-'66 Slant-6 cars used a direct-drive starter setup, similar to that used on US/rest-of-world '60-'61 Slant-6 cars, but nowtimes most of the parts cattledogs are American and that difference is not accounted for. The direct-drive starter uses a different ring gear than the gear-reduction starter used on US cars starting in '62. The Canadian-spec ring gear has an OD of 318mm and 148 teeth, and is meant for use with a starter having a 9-tooth, ø25m drive pinion. The US-spec ring gear has an OD of 312mm and 122 teeth, and is meant for use with a starter having a 10-tooth, ø33mm drive pinion.
The Canadian-type starter will not engage the US-type ring gear; it'll just sit there and spin. The US-type starter will not engage the Canadian-type ring gear; it'll clash.
Parts store "remanufactured" starters (of whatever variety) are generally a bad gamble; they tend to be junk, but please post a pic of the starter(s) you have on hand—here's hoping you didn't hand in your original when you bought the first parts store item. If you have a Canadian-type starter and a US-type ring gear, I have your get-out-of-jail card (10-tooth ø33mm drive unit for the Canadian-type starter) so you don't have to drop the trans or pull the engine to change the torque converter or flywheel; send me a PM.
If you decide to change to the US-type starter, you'll also need the correct "seal" (metal plate that goes between the starter and the bellhousing; it's different) and you'll have to reconfigure the starter control circuit.
