Ok, we replaced the heater core and re-installed the A/C-heater unit under the Dart Sport's dash. According to a vacuum line diagram, from the dash control a solid black line runs to the vacuum reservoir on the inner fender, and a black with green tracer stripe runs to the heater control valve we installed in the heater's 1/2" inlet hose.

Although we went with a Super Six intake and Carter BBD carb, the intake vacuum tree fitting is off the original 1-bbl intake (one large nipple and one small). I believe the tree off the Super Six actually has four nipples. The vacuum reservoir has a larger line that runs to the vacuum tree. What goes to the smaller nipple on the tree?

Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

There are two hoses connected to the vacuum reservior. One goes to the vacuum tree on the intake manifold. The other goes to the heater control in the dash. Be sure to connect them to the right place, they are marked I think. The reservoir has a check valve in it to hold vacuum when engine vacuum drops off. Hook it up backwards and no vacuum will get to the heater controls.

Here's the hose diagram from a 1975 Service manual. Different year than yours but might be exactly the same.

Thanks Craig,
That's exactly what I have for the '74 diagram. I'm OK with those hoses. What I need to know is what vacuum line goes to the tree, besides the one from the vacuum reservoir (there is another smaller nipple on my 1bbl tree). If it isn't needed, I'll just cap it off.

Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

Oh, I see now, I did not understand the original question!. The other nipple may connect to the EGR amplifier if it is still on our car. Look for diagrams in your manual or check the underhood hose decal. I'd have to do some digging in my books to find the answer but dont' have time at the moment. I do not remember how many hoses went to the tree on my 1975 Valiant that went to the Junkyard years ago. If you can't figure it out I can dig up some info when I have time.

Sorry to take so long getting back to your post, Craig. Someone told me the EGR line should be the only other vacuum line coming off the tree, except for the one going over to the vacuum reservoir (has the black one from the heater control also connected). I don't have an EGR or the amplifier, so that other nipple on the tree will be getting plugged.

Thanks,
Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

If you eliminated the EGR then you will need to plug the extra one. I think A-bodies with factory installed cruise control (a very rare option) would have had a third hose going to the tree.

My Super Six intake came off a '78 Volare. The tree on it had one larger nipple pointing straight up and three smaller ones going off at various angles. Needless to say, I replaced it with the stock one off the 1-bbl intake.

Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.