to roll out one a day. In 1922, no more than 150 Duesenberg ModelAs were manufactured, with only a total of 650 units sold over a period of six years. Model X (1926–1927) The Model X is a sportier version of the ModelA with a heavier and longer ( wheelbase) chassis and engine that enabled it to reach . The most notable differences between the Aand the X were that the latter had hypoid differentials and all its valves were on one side. The Duesenberg Model X chassis is an upgrade over the ModelA chassis, offering a reworked 260 cu. in. straight-8 engine, an overhead cam, with a new crankshaft, revised valve train, improved pistons and superior intake manifold. Power is 100 hp, which made driving at 100 mph possible. The chassis length increased to 136 inches, with additional reinforcements. Improved leaf springs are mounted above the frame rails, thus, lowering the center of gravity. The Duesenberg ModelX chassis is the rarest Duesenberg street production chassis ever made, with only thirteen ever manufactured. Only five of the Duesenberg ModelXs manufactured are known to have survived. Model J (1928–1937) The first Model J prototype was created in 1927 and the first cars were delivered in 1929, shortly before the onset of the Great Depression. About three hundred ModelJs were completed by 1930, short of the original 500-vehicle goal. The car's engine was based on the company's racing engines of the 1920s and was manufactured by another Cord company, Lycoming. It output , aided by dual overhead camshafts and four valves per cylinder, making it the most powerful car of its time. The ModelJ was capable of a top speed of , and in second gear. Duesenberg historian Randy Ema wrote that the ModelJ spurred change in engine design, "single-handedly (starting) the horsepower race that drove the number of cylinders from twelve to sixteen," but noted those engines still could not match the ModelJ's power output. Only the chassis and engine of the ModelJ were displayed, as the body and cabin of the car were custom built per custom for luxury vehicles at the time. The company's chief body designer, Gordon Buehrig designed around half of the ModelJ bodies, while the remainder were designed by coachbuilders around the world, including Gurney Nutting, Murphy, and Derham, among others. The J was available in two versions of chassis with a different wheelbase; a longer