I'm not really into 4 cyl engines, but that is some rocking HP he's making.
The article estimates it at the crank, as he's using an auto trans. I spoke with the owner at length. He confirmed that I "definitely have higher numbers" than he got when I shared my graph. Highest torque anyone's seen on an LD9 was 475 til then lol.
2001 Alero LD9
583 whp / 600 ft-lb