According to my Motor's manual, the only 6 available from '59 thru '64, in Ford 1/2 ton pickups, was the 223. The 240 replaced it in '65.
The 223 was an excellent engine, but it only had 4 main bearings. The 240 that replaced the 223, had 7 main bearings. Later, the 300 Ford engine, also with 7 main bearings, were available for heavier duty Ford pickups/trucks.
