1973 340, want more power.

Ok. All of that has been done except the o2 sensor. That wouldn't be on. 73/74 correct?

No. It's an aftermarket thing. You can get a bung, sensor, and gauge. Hook it all up and then you can always keep an eye on your 02 levels. So if you go to accelerate and get a part throttle bog. Or an off idle stumble. Or whatever else. You can see why. Maybe it's rich, maybe it's lean. Maybe it's something else. Just another tuning tool.