Seven and a half litres! I thought that must have been a typo until I looked it up. The engine alone must have weighed half a tonne.
A Buick 455 weighs about 600 lbs.
An iron headed Chevy 454 weighs about 675 lbs, less if it has aluminum heads.
You're average iron headed 350 Chevy weighs 575 lbs.
A 500 cube (that's 8.1 liters for you metric folks) Cadillac engine is about 575 lbs.... same as the average 350 Chevy.