68 383 vacuum question

[fireguyfire]

One more question for a guy reassembling a car he didnt tear down; my 68 383 with A/C. I am installing a new Edelbrock performer carb, and I am trying to figure out how many lines I need to provide vacuum to; I have one vacuum line coming through the firewall that goes to the heater/A/C box and provides vacuum to the actuators there, and then I am assuming I also need to provide vacuum from the same location to the vacuum cannister for the headlight doors. Can anyone tell me where the vacuum was taken from originally, and can anyone confirm that I should be good to go taking vacuum from the rear point of this new carb, and "T"ing it to feed both vacuum feeds I need? This carb has manifold vacuum take offs from the front and the rear (and also the vacuum above the manifold for the distributor assist). Anybody used one of these carbs and tied it to the original vacuum set up?

[fy469rtse]

The AFB carb has a designated port on the same side as distributor, small port, I will see if I can post a photo of mine , AVS but the same , factory port at rear, mine was a non A/C car but would imagine they added another point or tee to for use to ac line , headlight doors vacuum tee into power booster point , tee there ,
You didn't say what intake but I think the factory manifold had a port to thread in ,
Is the carby brand new with instructions , it will tell you there, if not i will find a photo to post for you, but back port on the carb good for vacuum  booster and vacuum for ac actuators ,

[fireguyfire]

Thanks for the info; heres a quick update; upon looking closer, tucked in behind the carb is the vacuum fitting off of the top of the intake manifold; it has a "Y" fitting screwed into it, and it has a smaller diameter side that angles toward the passenger side of the car (pointing upward of course) and a larger diameter end that points straight up from the manifold. I thought the vacuum hose from the heater/ac box would tie onto the smaller side as it is pointing that way, but the hose is too small to go over the fitting. I am assuming the larger diameter side of the "Y" is for the headlight vacuum, but it is quite large in diameter; can anyone help me out with this mess? I hate putting back together cars I didnt take apart, and I cant seem to find the answer in the shop manuals.

[Charger_Dart]

The way you described your fittings and what hoses connect to them is the way mine is. The hose to the HVAC vacuum doors is very small and the headlight hose is much larger. They fit fine on mine but are a snug fit.

[cdr]

If the hose is old & hard it wont stretch over the fitting,try trimming a 1/2 inch or so off the end. if not ,replace the hose.

[Troy]

The big port is probably for the power brakes. The headlight hose is relatively small and I have totally forgotten where it connects. I believe it goes first to the vacuum can under the battery tray and then through the lines to the headlight switch and then to the front of the car. The headlight hoses enter the car on the driver's side through a grommet up and to the right of the bulkhead connector.

Troy

[fy469rtse]

Photo's , it helps us by looking at images, I thought vacuum went to power booster tee, booster went to rear of engine , small tee for a/c
are restoring or just making it functional, post photos,

[fireguyfire]

Ok guys; I'm getting on top of this after more internet searches. The large side of the "Y" is for the power brake booster, the smaller side of the "Y" is for the "large" supply hose that goes to the vacuum cannister (headlights), which leaves the smaller again hose that feeds the heater/ A/C box; anybody know where this line ties in to get it's vacuum?

[Just 6T9 CHGR]

For a BB with AC there is a 3 port vacuum tree screwed into the rear of the intake.  The larger top port is for power brake booster (if equipped)
One of the smaller legs is for the headlight vacuum & the other is for the AC blend doors in the interior.  See pic below..

[fireguyfire]

Thanks; that sorts it out for me.