The 7 x 17.5 may have been the base tire listed on the sheet but not necessarily the tire that was most commonly used. there would have been a basic truck listed from the factory with no options and those would be the tires listed. when they came out and adv a new truck for sale at $1495.00. those would be the tires. dealers would order trucks with what tires and wheels they wanted and they would be an optional price. the old 7.50 x 16 was really the std tire used in those days
ron
