Actually it is (or was) a Ford F8. Which is a conventional tractor.
Convoy Company built the trucks special using the Ford cab in their own shops. The picture you have is of the origional configuration. Here is another picture of the same truck.
Later the trucks were reconfigured, still using the Ford cab into this set up.
A unique feature of that truck was the engine was moved back and the sleeper was under the cab.
Car carriers back then were often custom built leading to some very unique trucks.
Chris