To compare the performance fairly, you'd have to look at what the maximum range of the Spitfire is with a max allowable fuel load...and then load the '38 with enough fuel to give it comparable range. Now I'd need to dig out some source material, but I'd speculate that a '38 L can go further on internal fuel (no 310 gallon drop tanks) than a Spit can with a full fuel load. Heck, the '38 might go about as far on the mains (not even using the wing leading edge tanks). I need to dig out Bodies book again.