I would say this as additive. Before installing distributor rotate it by hand in the correct direction with ignition on an someone holding #1 towards engine ground. Make sure you have a good spark. This ensures ECU, wiring, coil, distributor is working and producing spark.
The service manual also tells you where the vacuum cannister should point. Or know in advance where it should point for the clearance with your engine. This points the rotor at #1 terminal on the cap, if you have done the above-mentioned items correctly. Some engines have little room for distributor movement without hitting stuff. Yes, you can just move wires a terminal, but that still doesn't solve the issue of timing adjustment.
The last item is you can set the engine at whatever initial you want lets say 10. Rotate until Timing mark on balancer is 10 BTDC. For points with a voltmeter rotate the distributor until the point just open. You are now firing #1 at "ABOUT" 10deg. For ecu align reluctor point to be on the coil magnet. Again you will be firing at about 10deg BTDC.


Cab, you know the 68-69 Hemi had 0 Initial timing from the factory right? I think there was even other engine that used a degree or 2 ATDC from the factory in the emission years.