Where to get vacuum from now????

[Vegas T]

Ok guys, maybe I'm just going dumb for a minute but I need some ideas. I have a 350 Turbo trans mounted to a 350 Chevy with a 471 blower and single Edelbrock 700 carb. My question because I'm drawing a blank is, where can I pick up vacuum for the modulator on the tranny? Everything I remember says use manifold vacuum, but I believe I have nothing but Boost below the carb due to the blower. Keep in mind the car is done so adding an ugly vacuum line now is going to kill me, maybe I can do an aluminum hardline....thoughts?

 

[Track-T]

on the edelbrock the small vac. fitting on the drivers side is modulator.
hardlines will work well,I used 3/16" brake line. 5' is about $6.00

 

[Track-T]

my vac. line is the black line.

 

[2old2fast]

I believe you're correct that you've altered normal vacuum , best to ask the blower MFG
or maybe edelbrock what their recomendation is....

dave

 

[PotvinGuy]

Under the carb, or from the manifold. Both will work. I've had your setup and tried both.
Under the carb will give softer shifts since the pressure there will always be less (i.e., higher vacuum) than in the manifold.
See which one you prefer. Don't worry about boost; it won't hurt the tranny.
For vacuum lines I use clear aquarium tubing. I like to be able to see if there is anything in the line that shouldn't be there. My EFI fuel pressure regulator once tore it's diaphragm and the motor started sucking fuel thru the vacuum line, which I could see. That line also fed the MAP sensor, the boost gauge and the distributor, so good thing I caught it right away.

 

[Vegas T]

Thank you guys for your replies, I am going to T into the line for my distributor and hopefully that works.

 

[railroad]

Your distributor could be manifold or ported vacuum. They are different.