Shew what he has is the VDO push button ignition system that used a 4 digit pin to start. These are know to go bad and no longer supported by VDO. One needs the wiring diagram for this system to figure out how to retire for a conventional ignition switch. Not sure if his gauges are impacted by this one off system.
1997 2400 SCR
5.7 Vortec / Bravo 2