Found my dads original 1971 duster!

340sFastback said
You can remove instrument cluster, join amp meter wires, and run the engine that way. Just make sure no other dash wires touch ground.

The scum bag shop might have amp meter wires on wrong studs behind dash.

Oh that’s good to know! It was amazing to hear it run for those brief seconds! Which wires are the amp meter wires ? I’m going to try to take the dash out today. Thanks!