Some of the rallycross cars were running about 660bhp with the zetec motor a few years ago in the UK.

If they use the ST170 / SVT engine they could get the numbers but the head would start to lift off the block above 600 unless they redrilled the block and installed thicker head studs.

At that sort of level you need to have a big budget motor, no question or it will last 2 mins.