There is a binding post under the front dash - on top of the scuttle beam (front cross member of the chassis), but under the dash, behind the instrument cluster. It's a plastic box with the cable that runs to the battery and the "hot" wires that run to the rest of the components in the front of the car all connected to one insulated bolt (post).
This should be a link to photos showing the binding post box:
Ahh..people...
The grounding post is up in the front of the car, under the condenser, radiator, and heater box. I'd find another good bolt screwed into the chassis to use for a ground.