[79FordBlake]

Is there supposed to be a timed vacuum port located in the front of the manifold for the vacuum advance? My vacuum advance is hooked up directly to the port on the driveside front of the carb. My Uncle has a completely unaltered stock 79 with a 351M with all emissions equipment in place and it has a vacuum port located in the front. I was wondering if mine should be like that or is it fine the way it is?

 

[79Time]

You should have the ported vacuum switch

 

[79FordBlake]

Do I use the same ported switch to hook up my egr valve? How many ports and what color coded ported vacuum switch am I supposed to have? How does it all hook up? Sorry for all the questions. Thanks for the help.

 

[Zebrafive]

My 78 F250 has a yellow three port vacuum switch in the themostat housing. One hose goes to the vacuum advance, one to the carb, and one direct to the intake manifold. Ford's idea is to use vacuum from the carb unlees the engine gets too hot. Then the ported vacuum switch switches the vacuum supply direct to the intake for full manifold vacuum which advances the timing and increases the engine speed until cool down occurs. After cool down the ported vacuum switch switches the vacuum supply back to the carb.