Do you use a timing light ?

[Ol' Ron]

The combustion cycle need more advance, when the engine is in cruise. That's why a modern ignition system has a vacuum advance. The load a matic works very well if it's in good operating condition. Same goes for the Vacuum brake on the old distributors. However the old engines ran on 60-70 Octane gas, with a lead additive in some cases. These ignition systems worked well, but as we know now, they weren't the most efficient.
Yes it works, but it can be made to work better.