Supercharged or Stroked 360

Thinking out loud...
Remember he's talking rear wheel hp. So it's a little more of a project to reach 480-500 at the crank. Not really hard to do but more of a project than a stock 360 with a cam. I've done it in a 422 with ported factory iron and a small hydraulic cam. If it was me I would not want it boosted. Especially with a carbuertor on it. There is way too much that can go wrong when the Gs are flinging things around at speed to want a blower/carb combo.
You bought a rebuilt engine with a problem. You need to have it looked at to find out why. If it's a bore issue and it needs to be bored, or the machining sucks and it needs to be bored, that block may not be good enough. So have it torn down and inspected. If the bores are round and straight then have it sonic tested to make sure that's good. If it passes that, have them install rotating assembly and move forward with a NA engine. A solid flat tappet, or (preferably) solid roller w/lifter bushings and a set of heads that flows 260 @ .500 will get you there.
No boost is easier to tune, much more forgiving, and most iportantly the power is smoothly managable. If you're road racing you want a bunch of torque, and just enough gear to reach the end of the longest straight at 10% past the hp peak flat out. This type of engine will be done at 6K or less.