What’s my first move??

Is your tachometer connected, with the inline resistor in place? I had found in the past that my 76 and a 78 parts car would not start if the tachometer was disconnected. It appears to do something to the signal on Pin 1. I never figured out what, but I did confirm it a couple of times. On the 78 I had the tachometer out and on the 76 I had the resistor removed which disconnected the tachometer.