Getting 900 hp from a well built big block is not impossible. Will it survive long? Probably not. Will it be reliable? Probably not. Does it use pump gas? Nope!!
With an engine that big, you have to have 14:1 compression and run racing fuel.
Not very desireable for the street.
I know that even my motor with it's estimated 650+ horsepower will be a nightmare in a 2400 pound car. But that's me - different
Venom_S