Best place for ground under dash?

Well, I used the lip on the back of the dash for the gauges and it works fine.

Thanks for the suggestions.

I used that lip for my gauges and an amplifier, and it intermittently cut out, and when the blinker clicked, the gauges all moved with it. Tick tock, tick tock, sort of thing. I moved my ground to a seperate bolt behind where the steering column goes through the firewall, and then ran a wire from the firewall side in engine bay, to the engine block, then from there to the battery. No more ticking. lol