This is modified THE THOUSAND-MILE WAR Scenario.

Main change is extra capacity for bombers, which will result in greater consumption of supply, to represent also fuel usage by planes.

All planes can use drop-tanks, but for some of them (those which do not had them included in original game) they provide no benefit. Drop-tanks should actually be mandatory used, when planes are flying on longer-range mission.
Definition of LONG-RANGE vary, depending of plane, but larger planes should use it all the time. "Larger" probably includes P-38.

WARNING!
B-24D should use drop-tanks for every bombing mission!
Changing its capacity would put it at different size, so needed airfield would be greater. This is the only way to keep it below 13000.

B-25C is experimentally modified to shorter maximum range, as I have found, that extra fuel was actually stored in bomber-bays, so it technically used drop-tanks for longer transfers. This have no effect in-game, because map is too small, to have more than 30 hexes between bases.