It is a 4 speed, dual coupling transmission. There is no torque converter on these units. It is a fluid coupling.
My '56 Coupe de Ville has one. Different versions with different valve bodies were made for GM's other makes. It's a strong, durable transmission with lots of torque. I wouldn't scrap it because it is certainly rare on a pickup truck.
The truck version is the heaviest of all the versions and weighs 435 lbs. in a pickup and 655 lbs in a bus.
With regard to swapping it out, at least with the car versions, there is no direct swap due to bell housing bolt patterns, etc. People who switch to a turbo 400, for example, have to fabricate everything.
