You probably already know, but you can utilize the two screws underdash (ash tray mount) for your gauge bracket. Very secure. I'll send you a pic how they mounted the tac in place of the fuel gauge,,,in 68. Very simple and I like it anyway. Lose the amp gauge, throw a 0-90 ohm fuel gauge in it's place. Just an opinion, the way I like it set up.
Green or black on you lol, I Iike the both.