550-600HP 4spd suspension help

What is his car running (ET and MPH)?

Yes, a bias ply slick will absorb the shock of the launch much better, giving you a chance to hook. Drag radials + high powered stick car = inconsistent 60' times....just my 2 cents.
he is running low 12s at about 112 in a 4000 lb 74 satalite