Wiring the 3 hole Gauge Cluster

[myoldchevytruck]

I emailed GMC Paul to ask for his expertise but I know things have been hectic in his neck of the woods so I was hoping there was a board member who was wiring saavy. A fellow board member referred my to GMC Paul's tips link for the cluster connector but I am still a bit confused.

I am re-wiring my 1969 SWB and I am using an after market harness (Rebel Wiring). So far, everything is going smooth. I am using a 3 hole bezel in my truck (I seen the difference between the two - same plug, different setup).

I have matched/used the following wires on the connector: #7 Pink, #9 Green, #10 Light Blue, #11 Dark Blue

I have the following wires left in my harness: oil pressure, water temp, tach (I am using an after market gauge pod)

AND A RED WIRE LABELED: GAUGE POWER

Other than the gauge wires in the connector, am I using anything else? How about the #6 black wire/ground on the connector - do I run that to a body bolt for ground?