Found my dads original 1971 duster!

Beautiful color!
I'd drive it and check the tires frequently to see if they get chewed up. If they do, as long as the wheels aren't also very close to the spring, replace the tires with something 10-20 mm smaller. Using spacers may require new longer lug studs, and will of course push the tire closer to the quarter panel. Do you have lots of clearance to the quarter?