Love the avatar - you've got one gorgeous looking car - very jealous.
To give you an idea on size these are very close to the Dart - in fact actually a little wider. The engine bay will easily take a 440 with extractors - not a common conversion as the Aussie road authorities are kill joys and they deem 440 cubes too much for a 3500lb car - go figure. Still nothing wrong with 408 small block...will put most of the Aussie Ford and GM stuff to shame.