Drive the tread off the old tires. They may be better quality than you can buy today.
Of the last 3 sets of Goodyear Regatta's I've had on my 91 and 99 Olds, 10 have had ply seperation or sidewall blowouts. The guy at Goodyear wouldn't do a thing for me. He claims I hit something in the road, which I never did. Then he said I drove on them flat. I said "well yes, you have to drive a few feet to pull over to the shoulder of the road after the sidewall blows out".