well, I'm done. The whole shebang...

I have a similar 408 stroker IMM just built for me and I got 523 hp @ 6000 rpm and 522 ft lbs of torque @ 4500 rpm. Granted, I have a match-ported LD4B, EQ heads, a Holley 850, and probably a different cam. I'd guess with your changes, you'd have closer to about 580 hp @ 6500 rpm and 560 ft lbs of torque @ 5000 rpm.