I second that. Chryslers 426 cubic inch (roughly 7 liters) had production bhp figures of 425bhp, only this is strongly believed to be a fib by chrysler to get round american maximum power laws of the time. The true figure is closer to 515bhp straight out of the box.

And this is an engine that was de-tuned from NASCAR spec for the roads. 900bhp it not an unrealistic power target from these motors.