Wow, both sound like nice rides. The 63 will be a monster. Will the dash be original or are you doing something custom? Doors original or custom? The key will be doing a dash unit that gives you the ability to have full video interface, Sirius, etc. Let me know what direction the interior is going.
Does the 70' have the factory radio? Are you replacing it?

Sure. I am getting ready to start my audio project for my 65. Is your car a couple or convert? Also, give me some info on your other vehicle, year, make, model, audio system.