Lots of big numbers being quoted without any knowledge of what the limits are. Forget the silly numbers from Scandy land I doubt if anyone has made a practical YB over 900bhp even Julian has stopped at 880bhp.
Even with a girdle blocks crack & there life span is very short. On pump fuel I know only one over 800bhp . For a practical road car 800bhp is near the limit & needs a refresh every 8k miles. On the drag strip on mega fuel & a Drop of the gas 1000bhp would be available for short bursts.