The distributor potentially could have been replaced with an 'early' unit somewhere along the line so you've still need to verify that you have the correct 'late' distributor in the engine.  The 'late' distributor is physically larger in diameter but if you're not adept at recognizing the differences in sizes, you'll need to pull the cap and check.  The 'late' distributor will have curved points, the advance springs under the breaker plate assembly, and the rotor will turn against the mechanical advance spring resistance CCW when you put pressure on it.  If you've got all these, then the distributor will indeed have both a mechanical advance and a vacuum advance whereas the 'early' or Load-O-Matic distributors are vacuum advance only.

Also, if using a timing light, the 'late' distributor will show a given amount of advance on the damper when speeding up the engine with the vacuum advance line disconnected if the mechanical advance curve is not 'froze' up.  I'd use the aforementioned methods of identification before doing this one as a frozen advance curve can send you off in the wrong direction.

Lorena, Texas (South of Waco)

thanx guys. so then this distributor is vaccum and centrifical advance then?

You can check out the points in the distributor for a quick check to see if you have the early (pre-57) or late ('57 and later) distributor.  If the points are curved, you've got the late and if the points are straight you've got the early.  Also, if you can see any advance springs with the distributor cap pulled loose, you've got the early.  The late model distributor has the advance springs under the breaker plate where you can't see them very easily.

Like 55Brodie said, the truck originally came factory equipped with the 'late' distributor but 40+ years after the fact, any thing could have changed.

Lorena, Texas (South of Waco)

hey guys. names eric. just became a new member.  now tot the question. I have a 1964 ford f100 with a 292. does this motor have the load o matic setup on it. if not what kinda advance system does it probably have. the distibutor is a single points one.