1966 Dart troubleshooting

Do you still have points in the distributer? If yes, I would start by checking/replacing them (or converting to electronic ign), set the gap/dwell properly. Make sure the timing is set correctly. After that, adjust the valves, to .010 intake and .020 exhaust, engine hot. After those things are correct, then work on the carb,
PS: Make sure the PCV system is working properly befor adjusting the carb. It does have an effect on the idle adjustment.