Be sure to get the heavy duty disconnect from a racing supply place like JEGS or Circle Track, not the flimsy 100 amp switch most of the online stores sell. You'll need one with at least 500 amps capacity, and if a 1000 amp switch is available, get that one. It really doesn't matter which circuit gets broken, positive or negative. Some of them are available with a bell crank and a remote handle so the operating linkage can be hidden under the dash with the doors locked for extra security.
Jerry
