"Triumph's enduring TR series was developed gradually, beginning with the TR2, which evolved into the TR3 and gained a new Michelotti shape to become the TR4, which in turn received a new chassis with independent rear suspension to spawn the TR4A. For the TR250, the body and chassis of the TR4 were mated with a 2.5-liter version of the company's straight-six. Breathing through twin Stromberg carburetors for the U.S. market, performance was similar to the TR4's. Visual differences included nose striping, some black paint on the grille and other detail changes." -- Simeone Automotive Museum