The law here in Alberta is that if it didn't originally come with seatbelts you don't need them. So for most vehicles in the 60's you don't need seatbelts if it didn't have them originally. However, if the vehicle is modified (as in you've changed from the original 30HP engine and original suspension to all modern suspension and 300HP), then you need lap belts at a minimum.
After seeing the pictures of that suburban I'm considering putting Juliano's shoulder belts in my '46 GMC I'm building.
Has anyone installed them in a 41-46 Chev/GMC?