An iron block will hold up just fine with a turbo, but it takes a lot of engineering and re-engineering and fabrication and parts-buying and tuning to make it work well (drivable, reliable).
Depending on how much money you have to spend on 'em vs. time and skill, either have 'em rebuilt and reupholstered or do 'em yourself or swap in some better-condition seats out of some other car.
Oh and he thinks their different because of the ash tray on the back of them. Was that an option too?