Wiring the oil pressure sender for Camaro gauge swap

Does anybody know what to hook up where? I bought the pre-wired Camaro gauge cluster from Gary, but I'm not sure which wire to hook up. Vehicle is '94 RMW. The existing harness has 3 wires in the connector (Orange, Tan, and Gray) even though the OEM sensor only had 2 pins that I could see. The wiring on the new gauge cluster has one extra black wire outside the regular multi-connectors, which I was assuming is for the oil pressure gauge but not sure. I didn't cut the harness apart to see where they all went. I emailed Gary but I haven't heard back yet, and I was hoping to finish up the wiring and light the car off before the weekend. Any help would be appreciated!