What engine designed to power medium duty trucks and heavy cars was also used in Chevy's intermediate and pony car?
Chevrolet L72: The L72 was a Big-Block engine produced by Chevrolet between 1966 and 1969. Chevrolet L72:  In 1969 the L72 was available via a Central Office Production Order (COPO) in Chevrolet's intermediate (Chevelle) and pony car (Camaro). Chevrolet Big-Block engine: The Chevrolet "Big Block" is a term for a series of large displacement V8 engines that have been developed and produced in the United States from the 1950s to the current day. Chevrolet Big-Block engine:  Chevrolet had introduced its popular small block V8 in 1955, but needed something larger to power its medium duty trucks and the heavier cars that were on the drawing board.
The Chevrolet "Big Block"