well in the -1a there is absolutelty no reason why u need a drop tank.
a -1a at 50 percent fuel carries the same amount if fuel as the -1d and -1c at 100 percent.
a -1a at 75 percent will give u aprox. 34 minutes of flying, and u can quickly drain the wing tanks empty while climbing the fight, infact ususally by the time u get to where u want to go u have about 80% fuel left, and this is very econimical because u are not OVERLOADED, yet u have plenty of fuel to stay for quit a while.
anything over 50% fuel to a -1a is like adding extra drop tanks, and since its not really a bomber, there is no reason to carry 1 1000 pounder, so u wont have to worry about the bomb rack.
the -1a is second to the -4 only in terms of dogfighting.
In my honest opinion i think its more efficent than the -4 because u dont draw as much attention to yourself.
Either way, u must really learn a corsair to fly it affectivly because it is a VERY UNFORGIVING PLANE.
If u mess up u can lose alot of Energy or stall among other things as well.