Importing a vehicle from USA to Alberta

So I'm looking for a late 70s Suburban that I plan to drop a cummins in and build a reliable daily driver out of. It's come to.my attention that there's a great number of them just across the border in way better shape for less than I can find one in comparable condition up here. I'm aware there's tons of services and brokers to do this, but I'm concerned about being able to register in Canada. Do I need an OPI? I've heard mixed opinions on that, and I have a natural concern of the challenges a 50 year old vehicle might have getting through the notoriously difficult OPI. I'm not buying something concourse quality; in fact I'm hoping to find something with good patina.. So the debate is... Is it worth trying to pull one out of the US?