The new 158 model was at last finished in late 1963 and developed into raceworthiness for the 1964 Formula One season, featuring an eight-cylinder engine designed by Angelo Bellei.
O novo modelo 158 foi finalmente terminado a finais de 1963 e converteuse nun coche solvente para a tempada 1964, cun motor de oito cilindros deseñado por Angelo Bellei.