Does anyone know why Jason used the port on the intake manifold for his vac advance instead of the carb?

Also, I am wondering about why the outside ignition module is needed. What does it do? The Pertronix module doesn't have one does it? Anyone?

Here is the pic John wanted you guys to see..
http://s160.photobucket.com/user/st...2jpg_zpsd43b4eaf.jpg.html?sort=3&o=0

Last edited by Deve; 09/24/2014 8:41 PM.
Deve

1950 Chevy 3100 Deluxe Cab
1950 Chevy 3100 Standard Cab
In the Stovebolt Gallery
The Think Tank
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