Cars of our vintage were designed for bias-ply tires, bias-ply tires were designed for said cars. Radials, steel belts, etc. came after the wide spread adoption of power steering, hence the reason why radials make driving cars of our vintage more difficult.
Are radials better tires (more durable, longer lasting, etc.)...absolutely. Are they better for cars of our vintage...no.
If you want great bias-ply repro tires, try Coker Tire...they're the premier supplier for vintage cars.