In 1950 the maximum length permissible for two axle double-deckers was increased to 27ft and the 8ft width limit was made available on all routes.

With the extra foot in length, Leyland decided to lengthen the wheelbase from 16ft 3in which had been used since the TD6/7 to 16ft 5in, the remainder of the extra length being in the rear overhang.

A new series of designations was used for the 27ft models beginning with PD2/10 for the 7ft 6in wide and PD2/12 for 8ft wide models continuing with other variations.

More differences were evident in the Leyland body design for the new models. They were given the `Farington` name, the same as the experimental versions of 1948.

The production body retained the 5 bay layout and familiar lines to previous models however the style of glazing was different. The glass was only slightly inset and having radiused corners  top and bottom. Sliding windows were incorporated into the main outline with their own radiused corners giving a neat and well finished appearance.

The increased dimensions allowed a greater seating capacity initially only 2 from 56 to 58 but soon examples appeared with 60 and 61 seats depending on the operator.

From 1950 production models remained almost unchanged until 1953 when production examples of the concealed radiator versions appeared at first to meet Midland Red requirements.

Production of the PD2/12 continued with variations until early 1957 which included platform doors (kit already produced) and also a Lowbridge.