If your instruments are 1/4" spade, you might want to stick with 1/4" spade and wire out to the reat of the car.
Problem you have is getting a suitable number of connections in a single plug.
May I suggest;
1. remove the steering column.
2. place the dash on the lower lip of the dash board area. Push your meters through the holes and make sure they all fit.
3. Place the dash on a table with block holding it up and mount all your meters.
4. Wire all grounds and power connections to two final connections.
5. Place the wired dash back on the car and lean it out, towards the cockpit. Use tape to hold it at about 90 degrees to the dash board panel.
6. Wire the sensors and "other" connections.
7. tilt the dash into place and secure with screws.
If you ever have to work on the dash, it will tilt out towards you.
Just a suggestion.
