The standard and optional engines were carried forward from 1964. The previous Spyder engine was replaced by the normally aspirated for the new Corsa. The engine was unusual in offering four single-throat carburetors, to which were added larger valves and a dual exhaust system. A turbocharged engine was optional on the Corsa, which offered either standard three-speed or optional (US$92) four-speed manual transmissions. The engine was optional on 500 and Monza models with manual or Powerglide transmissions. All engines got some of the heavy-duty internal parts from the Turbocharged engine for better durability.