By 1944 most C-47s had been modified with self-sealing fuel tanks in their wings, as was standard for US bombers and fighters, while the C-46 never received this modification.
This is an interesting fact that I've found in my research.
Basically, in 1944 they made a decision to plan for a troop carrier version of the C-54 to equip airborne units in the Pacific since at the time, they thought that there was a possibility of a long range airborne operation in the PTO.
However, this foundered upon the rocks of changes:
- Redesigning the C-54 wing would add 2,110 pounds to the weight of the plane.
- Fuel capacity would be reduced from 3,601 gallons to 2,712 gallons.
- Operational range of the C-54 would go from 3,700~ miles to 2,800~ miles.
- It would take until Feb/March 1946 for the C-54s with changes to come off the line in quantity; at which point....a better aircraft would be along -- the C-82.
They chose instead to equip TCGs in the PTO with C-46s as an interim, since the C-82 Packet was coming in Early 1946, with integral self sealing fuel tanks 'baked into' the design and an operational range of 4,200 miles.