The direct development of La-5FN fighter was Lavochkin La-7, the last of the Lavochkin's fighter used in WWII. By changes in the construction of the fuselage the speed and altitude performance of the aircraft improved again. La-7 was used since summer 1943.
The arnament was two or three 20 mm cannons.
More about Lavochkin LA-7 on Wikipedia
June 2009