In 1933, Chrysler decided to catch up with Ford and Chevrolet in engine cylinder count. The version of Chrysler's flathead-six engine was equipped with a downdraft carburetor and installed in the new 1933 Plymouth PC, introduced on November 17, 1932. However, Chrysler had reduced the PC's wheelbase from , and the car sold poorly. By April 1933, the Dodge division's Model DP chassis, with a wheelbase, was put under the PC body with DP front fenders, hood, and radiator shell. The model designation was advanced to 'PD'. The PC was redesigned to look similar to the PD and became the 'Standard Six' (PCXX). It had been the 'Plymouth Six' at the introduction and was sold through to the end of 1933, but in much lower numbers. In 1937, Plymouth (along with the other Chrysler makes) added safety features such as flat dash boards with recessed controls and the back of the front seat padded for the rear seat occupants