Modifications: 
        A-20A : attack version for USAF 
        A-20C : licensed version built by Boeing, nicknamed "Boston" by RAF 
        A-20G : licensed version for USSR, 7,478 built 
        F-3 : photoreconnaisance version 
        P-70 : night fighter 
A-20G was most numerous verison(over 2800 built)...A-20J had a glass nose to lead bomber formations. trival information for ya.