According to the GM Heritage documents, the standard tire size for the 1/2 ton in 1948 was 6.00X16 inch 6 ply. An RPO option was for 6.50X16 6 ply as well as 15" 8 ply tires. The original 6.00s were approximately 28 inches in diameter and the 6.50s 29 inches. I recently purchased a set of radials from Diamondback that are very close to the same size as the 6.00X16s. They are 195/80 R16 made by Yokahama and are their black wall "smoothies". I am very pleased with their ride quality and original looking profile.