1929 tire questions

[fred93]

Getting ready to purchase new tires for a 29 Tudor. I see lots of options online so I am confused.

What is the correct tire size for the 1929 Model A ?

I see tires out there that have nylon cords--but I remember some cars that I owned back in the day that had nylon tires and they had a tendency to get flat spots whenever the car sat for awhile. It would take some driving for them to get round again. I don't like that situation, so I guess nylon tires are out, unless they have been improved! I called Lucas Tire in CA and asked if the Olympic Tread Blackwall was a nylon cord tire and they said yes it was, but they said that they were NOT having problems with the tires getting flat spots after sitting. Anyone have any feedback on that? https://www.lucasclassictires.com/44...?categoryId=-1

Then I have seen several different sizes as well. 440/450 21 450/475 21
What is the correct size?