Engines

• The first generation of Firebirds, which included the 1969 Firebird, were not available with a 455-cubic-inch engine. The 1969 Firebird had three engine options available: a 250-cubic-inch, in-line six-cylinder, a 350-cubic-inch V-8 and a 400-cubic-inch V-8.
  
  

455's Arrival

• The 455-cubic-inch engine was a later arrival in the Pontiac Firebird. The maker did not release this big-block V-8 until the 1971 model year. The 335-horsepower, 455-cubic-inch V-8 was the standard engine in all 1972 Firebird Trans Ams.
  
  

455's Departure

• The 455-cubic-inch engine was slowly choked by stricter emissions regulations, to the point that the 1975 version put out only 200 horsepower. Pontiac finally laid the 455 to rest after the 1976 model year. The 455-cubic-inch engine was replaced, in 1977, by either the Buick-built 403-cubic-inch engine and the Pontiac 400-cubic-inch engine, depending on vehicle options.