Is the neutral safety switch properly connected? Will the engine crank "in gear?" Try it CAREFULLY with your foot on the brake!!!
If theft, that is a poor idea. Anyone who knows ANYTHING about an old Mopar knows you just jumper the relay......you can use "anything" metal including a nickel or penny!!!
You have a tach? "Or not" one effective theft prevention if you have a conventional ignition (NOT MSD/ CDI) is to put an unobtrusive switch to ground your tach wire.
Another.......if you have an electric pump......is a switch in the pump relay
If they show up with a "rollback" or a wrecker.......you need a wireless alarm system.