One more explanation here. There are many in the hobby who are adamant
that radial tires are a necessary upgrade for old cars. (I am not among that group; I'm an advocate for bias ply on the cars that were originally equipped with bias ply tires.) The problem is that the specialty radial tires with wide whitewalls are batch-produced in low quantities, and they are both very expensive and lack the quality construction and balance of regular street radials. So, many owners simply go to their local tire stores and have their cars fitted with whatever radial tires are in stock.This is a gross simplification, since there are, in fact, some quality radial wide whitewalls out there, but the tire choice requires buyers to do some research. In keeping with my bias ply bias, however, even radial wide whitewalls would not look completely correct on a car like this Chevy.