Wrong distributor for 69 318?

It's probably just misfiring - I don't have a good ear for this car or American V8s in general yet (used to aircooled 4cylinders and Italian stuff...) but I don't hear anything
that sounds like pinging.

By "unplugged" I mean I remove the vacuum line from the carb and cap off the carb.

I tried 5 and 10* as well, before trying 0*. Both had the same issue, although slightly lesser with less initial advance. I figure if I have to go to ATDC just to compensate for the vacuum advance adding too much timing,
then something is not right.

Rotor phasing actually sounds like a pretty likely culprit here, since it does seem to be a misfire more than a pre-detonation scenario. But if that's the case, how do I fix it? Can I? The rotor itself isn't adjustable on this distributor AFAIK.