vacuum line nightmares...

[drewdude92]

Alright i got a 72 chevy truck with a 350 small block and an edelbrock carb on it and i cant figure out where to plug the vacuum lines into. I need some help on where to plug the line coming from the tranny modulator. and the vacuum advance. THere are two inputs on the front of the carb one of them will suck my finger and the other wont.

[Wrenchbender Ret]

Usually there is a fitting in the manifold behind the carb that goes to the trans. Either one of the tubes on the carb can be used for vacuum advance. The one that has vacuum all the time is called manifold vacuum. The other one will have suction after you open the throttle a little ways. This is called ported vacuum. Some engines run better with manifold vacuum to the dist & some with ported. You will get better mileage with manifold vacuum so try it first. It will idle faster so you will have to slow down the idle speed a little. If it drops too much when you put it in drive or you can't idle it down you will have to use ported vacuum. It just takes a little experimenting.

[drewdude92]

alrght ima try the manifold vacuum one first