This is something that does not have separate wiring. You may be able to make it work but you need the wiring diagrams. I have swapped the XR7 wiring it to a couple standards. I used the udder dash, under hood and alt. wiring harness. I also made a jumper to make the courtesy lights work like they do in an Eliminator.
You may need to change to XR7 harness. It looks like it has tac lead from "C" terminal of ignition switch to junction not existing on standard harness. This connector splitts to coil and to pin #10 on printed circuit board for instrument pannel. The coil lead in main harness has internal resistor ( my info does not specify # Ohms. The non tac harness runs directly from "C" terminal of ignition to coil.
It also looks like the alternator harness (designated for tac) is needed to feed amp metre rather than idiot light. Several other pins on printed circuit board do not look like they are supported by standard harness, ie other gauges.
I think you need to follow what badcat did Change whole harness to XR7. Unless you want to essentially build custom harness to support all gauges.