They were bias ply, that was in the 60's and the best set I had were Pirelli's that were on the 40 when I bought it. I drove both cars halfway across the country, the 40 from San Diego to Dayton, Ohio in 62 and the 36 from Dayton to Camp Pendleton in 64. One thing about driving a straight axle car or truck, you drive it, it doesn't drive you.