I don't think it matters whether the tire is bias ply or radial. All that matters is the shape of the tire bead. I use modern radials on original 1939 Packard rims with no air loss. I used to run tubeless bias plies on my Cadillac as well with no problem.

Modern tires are designed to run tubeless be they bias ply or radial.


1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)