Besides the marketing aspect of Loadflite ( after all, in a truck the name
inspires an extra level of hauling ability ) in those days when every car
maker had some type of O-Matic or other futuristic sounding name for the
features of the car, the two transmissions are basically the same as Rodger
noted.
>From a practical, dirty fingers and skinned knuckles aspect of them, after
the aluminum case appeared in 62 they were the same. I believe some had a
shorter output shaft and case depending on the truck they were to be
installed in, and this is a stretch of memory, some also had provisions for
retarders ( a type of braking device to alleviate some of the work on the
service brakes )
Mikey
62 Crown Coupe