Paxton Super charger

Ok I have been thinking about the motor I would like to do for my duster.I was planing on a stroker but then got to looking into superchargers.I was planing on a 408 with about 500hp 500tq.I was think about building a 400hp 360 9.0.1 comp and running the paxton supercharger at about 9psi of boost.What kinda power gain do you think I would expect out of the setup.I would like to get 500hp 500tq but would like to get it at the lowest Rpm.Street/Strip car.Car will be about 3400lbs 3.73 gears 4 speed when I am done.