I've been hoping to find a USAAF equivalent with good primary reference material but haven't been successful for a free source. This outfit sells PDF for about $19 a pop: http://www.flight-manuals.com/index.html
For the above, I would suggest the following two sites:
The first site has a plethora of actual flight testing reports on many WWII aircraft. If you scroll down to the bottom of the page for a given aircraft, you can also find links to additional related materials. The second site contains the actual pilot flight training, flight operating instruction, erection & maintenance manuals, and more for a wide variety of WWII and later aircraft.
FYI: I've been looking at the F4F and F6F data and coming up with range reductions vs. stock without drop tanks. So source reference data can be a two edged sword. A big part of that is that range formula that the Navy used presumed a 20 minute combat interval at military power.
From the "Aircraft Characteristics & Performance" and "Standard Aircraft Characteristics" publications I've seen, for its calculations of combat radius the USN generally used the following as standard parameters:
20 minute warm-up; 1 minute take-off; 20 minute rendezvous, climb to 15,000 feet; cruise out at 15,000 feet using engine settings for maximum range; release drop tanks upon entering combat; 20 minutes of combat using military power and war emergency power; and cruise back at 1,500 feet. Also included was a reserve of fuel equal to the amount consumed in 60 minutes of cruising using engine settings for maximum range.
That reserve fuel amount inclusion in the combat radius calculation greatly reduces the non-drop tank radius, since that reserve eats up a much larger share of the starting fuel as compared to when a drop tank is in use. From the ACP for the F6F-3, the combat radius on internal fuel only was 120 nautical miles; with a 150 gallon drop tank, the radius was 335 nm. (Carrying a 1,000 lb bomb in addition to the drop tank reduced the radius only slightly, to 310 nm. The radius while carrying six 5" HVAR and a drop tank was 305 nm.)
The ACP for the F4F-4 lists a combat radius of 105 nm on internal fuel; 245 nm with one 58 gallon drop tank; and 325 nm with two 58 gallon drop tanks.