Good plan on doing the carb rebuild! You stated the timing was way off from factory specs, what was it? With the old LOD using the stock timing specs dosent work the best with today's fuels what did you set your base timing to now? With these LOD systems I start with at least 10 or 12 degrees and tune from there to see what the engine likes. To get your tune more accurate you will need the use of a tach / dwel meter especially if your Distribitor is still using the stock type points.
A good tune up follows this order of work
1. Set the plug gap .034.
2. Set the points basic setting to .025 after its runing set the Dwell Angel to factory spec of 38 degrees.
3. Now you need to set the timing at 10 to 12 degrees base timing this may need to be changed to as much as 16 degrees BTDC all depending on how your engine responds with any hint of pinging under more than a slight load (going up a small grade) back off timing a little at a time until it stops.
4. Set the Idle mixture to its Lean Best Idle.
5. Set the curb idle speed to 500 RPM.
6.Repeat 4. & 5. To see if it improves anymore.
You might also test your coils output with the volt / ohm meter as well as the plug wires and cap for their resistance readings are in spec. Good luck in your tuning