W block

The birth of the Mark IV 396 for public consumption occurred back in 1965. Its predecessor, the Mark I, started in 1961 on the drawing board, was finalized and built in late 1962, and was unveiled in race trim in 1963. It set the racing world on its collective ear at Daytona and other races, and then it disappeared, going back to Chevrolet Engineering for further development. Seeing that you could step up and possibly own the Marilyn Monroe of big-block engines, serious racers and enthusiasts had to sit on their hands for two full model years (1963 and 1964) before the son of this absolute powerhouse could be ordered.