battery cut off switch

Fellows, please read, see what you think, and comment on this.

I am looking at the 1970 Plymouth service manual for the 340. Think first in terms of the stock setup. From the positive side of the battery you have heavy wire going to the starter and a lighter wire going to the starting relay (B terminal). The starting relay has terminals for (B)attery, (S)tarter (I)gnition and (G)round. The I wire feed goes to the ignition switch via the bulkhead. The control wire from the S terminal goes to the starter solenoid. And the B terminal has a wire feed going to the fusible link and from there to the bulkhead and from there the ammeter, number 1 link, then branches out into headlight switch, horn, etc, another separate feed back through the bulkhead and to the B terminal of the alternator.

That said then, can’t you then just run from the positive terminal of the battery to a two terminal master cutoff switch and have wires as previously described run to the starter and to the starter relay from cutoff switch terminal farthest away from the battery? On that same terminal attach everything else (fuel pump with link, etc). Won’t that kill power to everything? Just make sure the feed wire from the battery to the master cutoff switch is heavy gage as well as the wire cranking the starter. The control wires can be the same gage as stock. The master cutoff switches are sold on Ebay Motors all the time for about 16 bucks.