Faced with an ever-aging fleet of cars and growing traffic levels after WWII, the American railroads embarked on an ambitious car building program. The Postwar AAR boxcar design that developed became one of the most important freight car designs ever. Featuring a 10-6 interior height and in both forty foot and fifty foot lengths, the majority of boxcars built between 1945 and 1960 were based on this design. Although standard designs, over the years these cars were built with various ends, roofs and doors. Branchline offers a variety of different parts in order to allow us to produce accurate models of most varieties of these important postwar boxcars. We have a variety of different ends, roofs and doors available and the correct parts are included in each decorated kit. We make every effort to be sure that the cars you buy will be as correct as we can make them. We've done the homework so you don't have to! Our 50' double door boxcar kits feature: 8' and 7' Youngstown doors, 7 or 8 rung ladders, three varieties of roofs, five varieties of accurate postwar ends, and accurate paint and lettering. We offer four road numbers on each road names. If a four pack is available, simply order the four pack which includes one of each car number. If a three pack is listed you will need to order both the three pack and the single car to get all four numbers.