http://www.newagegto.com/forum/index.php?showtopic=1760

Also a ? how big does an engine have to be to be a "big block"?

The term "big block" or "small block" is used to differentiate between engines of a common manufacturer. It does not necessarily indicate any specific size. For example, Chevy had big and small block engine families as did Chrysler and Ford. Pontiac did not. The block on a 326 Pontiac is the same size as the 455. So Pontiac did not have "big" or "small" block engines. :( (They were all big and heavy!)