The best allied fighter pilots have been the soviets

[Franek Grabowski]

Art
I remember about your account but I cannot verify it against all the Cobras used by Soviets. Personally, I believe those modifications concerned some aircraft of Air Defence units. Anyway, the key to Soviet success with the type is that the aircraft was flown in intended role of a fighter. Airacobra outperformed most of Soviet types, and for a certain period it was the fastest aircraft on its operational altitude. Altitude performance was on par with such aircraft like Spitfire V or Me 109F, but better than that of Yaks and LaGGs, most common at the time.
One thing about comparisons, we should not compare apples and oranges. Number of sorties, number of combats, flighttime, operational goals, actual results of combats, all those factors should contribute in such statistics. Also, considering that many of victories were shared ones, perhaps it would be wiser to discuss the problem on a unit level, rather than individual pilots.