If he is making around 500 hp at the crank, he may get a 6.50 or so around 104 ,105 mph. But he said no big port job on 452 heads and the cam may be a little big possibly, with a 410 gear. I don't know though, I'm just shooting from my hip with a few combos I did at that weight , with me in it. How much HP can you squeeze out of a 452 head with just a clean up?