You started it will start after it coold down. Sounds like an electrical resistance somewhere. Could be one of the ground wires or connections. My 66 Monacos 383 had a small bad spot in the main ground one time, a mechanic friend of mine found it by taking the wires and bending them until he found a spot which did not bend, due to the wired arced, melted and recooled. In the beginning it would start cold, but when heated up after driving would not. After a while would not start at all. Don't know if it will help, but you will know what it is not.
