The only things I could find in web searches indicates that your Firestone bias ply tires are manufactured and sold with the understanding that they are for use primarily as display show pieces on restored or vintage vehicles, with limited driving usage at highway speeds of 65mph and less.
If you want a tire that's going to be designed to run at regular highway speed levels and not limited usage, you're going to need to find an appropriate radial and likely some newer wheels to run them on. I didn't dive in to see if there are similar size/style radials out there, but guessing that if they do exist, they are going to be $$$$$.
