The Buick V6, popularly referred to as the 3800 in its later incarnations, originally and initially marketed as Fireball at its introduction in 1962, was a large V6 engine used by General Motors. The block is made of cast iron and all use two-valve-per-cylinder iron heads, actuated by pushrods. The engine, originally designed and manufactured in the United States, was also produced in later versions in Australia. It was the first six-cylinder engine designed exclusively for Buick products since the Buick straight-six was discontinued in 1930. The 3800 was on the Ward's 10 Best Engines of the 20th century list, made Ward's yearly 10 Best list multiple times, and is one of the most-produced engines in history. To date, over 25 million have been produced. In 1967, GM sold the design to Kaiser-Jeep. The muscle car era had taken hold, and GM no longer felt the need to produce a V6, considered an unusual engine configuration in North America at the time. The energy crisis a decade later prompted the company to buy the design back from American Motors (AMC), who had by that point bought Kaiser-Jeep, and the descendants of the early 231 continue to be the most-common GM V6 as it developed into a very durable and reliable design. Though the pre-3800 rear-wheel drive (RWD) V6 uses the Buick, Oldsmobile, Pontiac (BOP) bellhousing pattern, an oddity of both the front-wheel drive (FWD) and RWD 3800 V6 is that although it is a 90° V6, it uses the GM 60° V6 bell housing (Metric Pattern). For use in the FWD applications, the bellhousings on the FWD transmissions are altered slightly. This engine has the cylinders numbered 1-3-5 on the left-hand bank (front bank for FWD applications) and 2-4-6 on the right-hand bank, the number 1 cylinder being the furthest from the flywheel end. The firing order is 1-6-5-4-3-2. The engine was produced at the Flint North plant in Flint, Michigan, with engine blocks and cylinder heads cast at the Grey Iron plant (now the GM Saginaw Metal Casting Operations plant) at 1629 N. Washington Avenue in Saginaw, Michigan. It is a derivative of Buick's aluminium V8 family, which also went on to become the Rover V8, another engine with a very long life (1960–2006) Fireball V6 The first engine in this family was introduced in 1961 for the 1962 model year Buick Special with Buick's engine, the first V6