Mechanical advance is totally separate from the vacuum advance. Setting the timing i described above has nothing to do with racing, every car i set this way and they run great. the more initial timing you have will help the engine idle and run much better and pull more vacuum. the factory setting of 10 degrees is not enough. All vacuum advance does is pull in more advance when the engine is at the least amount of load when the engine produces the most vacuum. It is primarily intended for gas mileage. I don’t even hook up the vacuum advance on these cars, the mechanical advance does everything you need providing the distributor is not worn out.
