97BlackStang

Which is better for a street car, maybe a few times the track.

GreyStang

Most cars with distributors use BOTH

PRO50SC

Yeah, up until the early eightys. Those are a thing of the past.

Poobs

Before computers were used to monitor and control ignition timing cars used both types of timing advance. The combined effect of the vacum advance and the centrifugal gave the motor optimum timing under all driving condition. They simply do diferent jobs.
For an all track car the centrifugal ( mechanical)advance is the most important.