Among the first standard boxcar designs adopted by American railroads, the WalthersMainline 1937 40′ AAR Modified Boxcar features: One-time run of these roadnumbers, order now, limited quantity available! 1000s used in general service late 1930s to 1980s Based on taller cars built with 10′ 6′ interior height featuring: 5-5 Dreadnaught ends Murphy panel roof Wood running board 6′ Youngstown doors AAR (tab) side sills Correct 33′ RP-25 turned-metal wheelsets Proto MAX(TM) metal knuckle couplers