kill switch

By "ohm meter" I think you mean ammeter. NO!!! No switch in the car is that big, it would have to carry all alternator/ vehicle current, might be as much as 40 amps or more

Look up and read the MSD destructions. I believe you ground the white wire which would be used with a breaker points distributor. Without an electric fuel pump, this would be your best bet.

There also exist fuel shut off valves, but it might be cheaper to buy a 3 hole fuel selector valve and just plug one port. Figure out which ports pass fuel with the coil energized and use them. Then just wire to a switch, through a fuse and to switched ignition and the thing will start and run just fine----until the carb goes dry.