As there are many Canadians on the site, I thought I would pass on a tip when bringing in parts or even vehicles.
Tell the shipper or broker to use tariff code 9966.00.00 Basically any vehicles 25 years old or more or ANY items for use with those vehicles are duty free.
The following vehicles, manufactured more than 25 years prior to the
date of importation, and articles for use solely or principally with those
Motor vehicles principally designed for the transport of persons or
goods (other than vehicles specially designed for travelling on snow,
golf cars and similar vehicles, and dumpers designed for off-highway
If you have paid duty, you should be able to go back and have it returned by showing the parts are for an old vehicle.