NHRA rules

You'll need a minimum of two 3/8" hold downs (threaded rod works) for hold downs. J hooks are not legal. The bolts (or rod) will need to pass through the floor. If you don't have a rear firewall than you'll need the sealed battery box.

In addition to the cut off switch (Moroso or Flaming River makes them) you'll also need a relay wired into the alternator because the switch has to be wired into the positive battery cable. You'll need the relay for the alternator because otherwise it will just feedback when the switch is thrown and the engine will keep running. When the switch is thrown it will need to kill all power to everything, not just the ignition, but the fuel pumps, lights and anything else you run off it.